Fix missing language in unit test
If the project as no language, ctdep.clib_compiler
is None in get_pcap_lib_version() and it raise an exception.
-project('dependency factory', meson_version : '>=0.40')
+project('dependency factory', 'c', meson_version : '>=0.40')
dep = dependency('gl', method: 'pkg-config', required: false)
if dep.found() and dep.type_name() == 'pkgconfig'
