fix(main/gap): do not symlink include/gap/src to itself

Detected in termux_step_massage:

find: File system loop detected; ‘./include/gap/src’ is part of the same file system loop as ‘./include/gap’.

packages/gap/Makefile.rules.patch

@@ -9,3 +9,12 @@
  	
  	# install a wrapper shell script invoking the real GAP executable as $(bindir)/gap
  	$(INSTALL) -d -m 0755 $(DESTDIR)$(bindir)
+@@ -658,8 +658,6 @@
+ 	$(INSTALL) -m 0644 $(builddir)/build/version.h $(DESTDIR)$(includedir)/gap
+ 	$(INSTALL) -d -m 0755 $(DESTDIR)$(includedir)/gap/hpc
+ 	$(INSTALL) -m 0644 $(srcdir)/src/hpc/*.h $(DESTDIR)$(includedir)/gap/hpc
+-	# Create a symlink to support packages using `#include "src/compiled.h"`
+-	ln -sfn . $(DESTDIR)$(includedir)/gap/src
+ 
+ install-libgap: libgap.la
+ 	$(INSTALL) -d -m 0755 $(DESTDIR)$(libdir)