msgfmt: Fix another buffer overrun.
Reported and patch by Joshua Root <jmr@macports.org>
at <https://savannah.gnu.org/bugs/?56126>.
* gettext-tools/src/write-java.c (write_java_msgid): Allocate memory for the
trailing NUL byte as well.
* gettext-tools/src/write-csharp.c (write_csharp_msgid): Likewise.
