Welcome message in persistentRStudio is printed using `cat()` instead of `message()`

[calicule]

Hi, thank you for cloudyr!

I'm trying to install a package (minqa) which contains in its Makevars:

PKG_LIBS = `$(R_HOME)/bin/Rscript -e "Rcpp:::LdFlags()"`

When I install this, the welcome message gets added to the linker command as follows:

g++ -shared -L/usr/local/lib/R/lib -L/usr/local/lib -o minqa.so altmov.o bigden.o biglag.o bobyqa.o bobyqb.o lagmax.o minqa.o newuoa.o newuob.o prelim.o rescue.o trsapp.o trsbox.o trstep.o uobyqa.o uobyqb.o update.o updatebobyqa.o # Welcome to RStudio Server on Google Compute Engine! Today is Wed Mar 14 18:49:17 2018 -lgfortran -lm -lquadmath -L/usr/local/lib/R/lib -lR

Wrapping the welcome message in message() rather than cat() fixes this problem.

See https://github.com/cloudyr/googleComputeEngineR/pull/99 for a fix.

[MarkEdmondson1234]

Thanks very much for the fix! Unintended consequences of using cat, will keep that in mind