convert-archive.in uses "gcc" instead of $CC

[Ryan Schmidt]

In gettext 0.18.1.1 at least, gettext-tools/misc/convert-archive.in tries to 
compile something using the program "gcc" instead of using the value of the 
environment variable $CC like the rest of the gettext compilation does.


[snip]
    # Set a nonstandard variable, for a good-looking cvs history.
    cvsuser=bruno
    gcc -shared -fPIC -O cvsuser.c -o cvsuser.so
    cvsuser_hack=`pwd`/cvsuser.so
[snip]