Makefile: fix NO_PERL bug with gitweb

When the user has defined NO_PERL, we want to skip building
gitweb entirely.  However, the conditional to add
gitweb/gitweb.cgi to OTHER_PROGRAMS was evaluated before we
actually parsed the user's config.mak. This meant that "make
NO_PERL=NoThanks" worked fine, but putting "NO_PERL=NoThanks"
into your config.mak broke the build (it wanted gitweb.cgi
to satisfy "all", but the rule to build it was conditionally
ignored, so it complained).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -365,9 +365,6 @@ ALL_PROGRAMS = $(PROGRAMS) $(SCRIPTS)
 
 # what 'all' will build but not install in gitexecdir
 OTHER_PROGRAMS = git$X
-ifndef NO_PERL
-OTHER_PROGRAMS += gitweb/gitweb.cgi
-endif
 
 # Set paths to tools early so that they can be used for version tests.
 ifndef SHELL_PATH
@@ -1280,6 +1277,7 @@ $(patsubst %.perl,%,$(SCRIPT_PERL)): % : %.perl
 	chmod +x $@+ && \
 	mv $@+ $@
 
+OTHER_PROGRAMS += gitweb/gitweb.cgi
 gitweb/gitweb.cgi: gitweb/gitweb.perl
 	$(QUIET_GEN)$(RM) $@ $@+ && \
 	sed -e '1s|#!.*perl|#!$(PERL_PATH_SQ)|' \