The file has been redundant since it was first added [1]. It was never
listed in configure.ac (or configure.in) in AC_CONFIG_FILES. Therefore
autoconf has never produced help/C/Makefile.in and ./configure has never
produced help/C/Makefile. Therefore it isn't used during the build and
install of GParted. Remove it.
[1] 46ca7c74dc
Added code hooks to prepare for GParted Manual
Closes!24 - Port to GNOME 3 yelp-tools documentation infrastructure