codesign --timestamp=none is not supported on 10.6

Change-Id: Ie1e853fd1dd3154c6805eb8129c35a49150b458c
Reviewed-on: https://gerrit.libreoffice.org/3806Reviewed-by: Tor Lillqvist <tml@iki.fi>
Tested-by: Tor Lillqvist <tml@iki.fi>

solenv/gbuild/platform/macosx.mk

@@ -163,7 +163,7 @@ $(call gb_Helper_abbreviate_dirs,\
 		ln -sf $(notdir $(1)) $(basename $(1)).jnilib &&) \
 	$(if $(MACOSX_CODESIGNING_IDENTITY), \
 		$(if $(filter Executable,$(TARGETTYPE)), \
-			codesign --timestamp=none --identifier=$(MACOSX_BUNDLE_IDENTIFIER).$(notdir $(1)) --sign $(MACOSX_CODESIGNING_IDENTITY) $(1) &&)) \
+			codesign --identifier=$(MACOSX_BUNDLE_IDENTIFIER).$(notdir $(1)) --sign $(MACOSX_CODESIGNING_IDENTITY) $(1) &&)) \
 	$(if $(filter Library,$(TARGETTYPE)),\
 		otool -l $(1) | grep -A 5 LC_ID_DYLIB > $(1).exports.tmp && \
 		$(NM) -g -P $(1) | cut -d' ' -f1-2 | grep -v U$$ \