patch 8.2.1495: "make clean" may delete too many files

Problem:    "make clean" may delete too many files.
Solution:   Do not delete $APPDIR. (closes #6751)

src/Makefile

@@ -2910,8 +2910,7 @@ clean celan: testclean
 	-rm -f testdir/opt_test.vim
 	-rm -f $(UNITTEST_TARGETS)
 	-rm -f runtime pixmaps
-	-rm -rf $(APPDIR)
-	-rm -rf mzscheme_base.c
+	-rm -f mzscheme_base.c
 	-rm -rf libvterm/.libs libterm/t/.libs libvterm/src/*.o libvterm/src/*.lo libvterm/t/*.o libvterm/t/*.lo libvterm/t/harness libvterm/libvterm.la
 	if test -d $(PODIR); then \
 		cd $(PODIR); $(MAKE) prefix=$(DESTDIR)$(prefix) clean; \

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1495,
 /**/
     1494,
 /**/