fix run statement for non-shell executables

[lenerd]

Using '.' tries to interpret the given file as a shell script.

Note that build.sh is still executed this way but in that case the hardcoded filename implies that it should be a shell script.

[lenerd]

My intention in this change was to allow running arbitrary executables, e.g. python scripts or the compiled ABY/Scapi/... program directly, instead of having to call a shell script. Is there any reason to restrict this to Bash-Scripts (or whatever the standard shell on the used image is)?

$ ls -l
total 4.0K
-rwxr-xr-x 1 lennart users 46 Dez  6 16:14 hello.py
$ cat hello.py
#!/usr/bin/env python3

print("Hello World!")
$ ./hello.py
Hello World!
$ . ./hello.py  # <-- as in MATRIX
./hello.py:3: unknown file attribute: H

I have updated the branch corresponding to this PR: https://github.com/cryptobiu/MATRIX/compare/1.2...lenerd:lenerd/fix-run