Remove obsolete appimage patches
* Makefile.am (EXTRA_DIST): Update accordingly. * patches-appimage/kleopatra/require-ecm-104.patch, patches-appimage/kmime/set-cxx-standard.patch, patches-appimage/libkleo/set-cxx-standard.patch, patches-appimage/okular/ 0001-Include-stdarg.h-for-va_start-and-va_end.patch: Removed. * src/appimage/appimage.mk.in, src/gpg4win.mk.in: Update versions in minimum required version hacks.
The patches are either upstream or not neccessary since we set
a recent enough KF5 Version.