fixed courier-authlib "make install" error on Ubuntu.

[mumumu]

I tried to make install after building courier-authlib after patching #9, but got the following error on Ubuntu 18.04 LTS.

I confirmed this error cannot be reproduced on Fedora 28. On Ubuntu (or Debian maybe), it seems that we must specify .la file by dependency order.

This fix does not affect on Fedora 28.

$ sh INSTALLME courier-authlib https://github.com/svarshavchik/courier-libs.git
$ cd courier-authlib
$ ./configure --prefix=/home/mumumu/local
$ make
$ make install

(.snip)

make[4]: Leaving directory '/home/mumumu/build/courier/courier-authlib'
libtool: install: /usr/bin/install -c .libs/authtest /home/mumumu/local/sbin/authtest
libtool: install: /usr/bin/install -c .libs/authenumerate /home/mumumu/local/sbin/authenumerate
libtool: warning: relinking 'libcourierauthsasl.la'
libtool: install: (cd /home/mumumu/build/courier/courier-authlib; /bin/bash "/home/mumumu/build/courier/courier-authlib/libtool"  --tag CC --mode=relink gcc -g -O2 -Wall -Ilibs -I./libs -export-symbols-regex "^auth_sasl|auth_sasl_ex|auth_sasl_extract_userid\$" -avoid-version -o libcourierauthsasl.la -rpath /home/mumumu/local/lib/courier-authlib authsasl.lo authsaslcram.lo authsasllogin.lo authsaslplain.lo authsaslfrombase64.lo authsasltobase64.lo libcourierauthcommon.la libcourierauth.la )

(... Note by mumumu, the following line is the root cause of install error. )

libtool: warning: 'libcourierauthcommon.la' has not been installed in '/home/mumumu/local/lib/courier-
authlib'

libtool: install: /usr/bin/install -c .libs/authpasswd /home/mumumu/local/sbin/authpasswd
libtool: relink: /usr/bin/nm -B  .libs/authsasl.o .libs/authsaslcram.o .libs/authsasllogin.o .libs/authsaslplain.o .libs/authsaslfrombase64.o .libs/authsasltobase64.o   | sed -n -e 's/^.*[      ]\([ABCDGIRSTW][ABCDGIRSTW]*\)[  ][      ]*\([_A-Za-z][_A-Za-z0-9]*\)$/\1 \2 \2/p' | sed '/ __gnu_lto/d' | /bin/sed 's/.* //' | sort | uniq > .libs/libcourierauthsasl.exp
libtool: relink: /bin/grep -E -e "^auth_sasl|auth_sasl_ex|auth_sasl_extract_userid$" ".libs/libcourierauthsasl.exp" > ".libs/libcourierauthsasl.expT"
libtool: relink: mv -f ".libs/libcourierauthsasl.expT" ".libs/libcourierauthsasl.exp"
libtool: relink: echo "{ global:" > .libs/libcourierauthsasl.ver
libtool: relink:  cat .libs/libcourierauthsasl.exp | sed -e "s/\(.*\)/\1;/" >> .libs/libcourierauthsasl.ver
libtool: relink:  echo "local: *; };" >> .libs/libcourierauthsasl.ver
libtool: relink:  gcc -shared  -fPIC -DPIC  .libs/authsasl.o .libs/authsaslcram.o .libs/authsasllogin.o .libs/authsaslplain.o .libs/authsaslfrombase64.o .libs/authsasltobase64.o   -Wl,-rpath -Wl,/home/mumumu/local/lib/courier-authlib -L/home/mumumu/local/lib/courier-authlib -lcourierauthcommon -lcourierauth  -g -O2   -Wl,-soname -Wl,libcourierauthsasl.so -Wl,-version-script -Wl,.libs/libcourierauthsasl.ver -o .libs/libcourierauthsasl.so
/usr/bin/x86_64-linux-gnu-ld: cannot find -lcourierauthcommon
collect2: error: ld returned 1 exit status
libtool:   error: error: relink 'libcourierauthsasl.la' with the above command before installing it
Makefile:968: recipe for target 'install-pkglibLTLIBRARIES' failed
make[3]: *** [install-pkglibLTLIBRARIES] Error 1
make[3]: Leaving directory '/home/mumumu/build/courier/courier-authlib'
Makefile:1789: recipe for target 'install-am' failed
make[2]: *** [install-am] Error 2
make[2]: Leaving directory '/home/mumumu/build/courier/courier-authlib'
Makefile:1483: recipe for target 'install-recursive' failed
make[1]: *** [install-recursive] Error 1
make[1]: Leaving directory '/home/mumumu/build/courier/courier-authlib'
Makefile:1783: recipe for target 'install' failed
make: *** [install] Error 2