We don't want libxmlsec on iOS, I think

It would require NSS which I just decided to skip. If/when we patch it
to support native iOS (and OS X?) crypto APIs, re-consider. Or
something.

Now the TiledLibreOffice iOS demo app builds again.

Change-Id: I2816a49bbdbde5a8f9d3b9fcdfff420bdca05ff8

bin/lo-all-static-libs

@@ -44,8 +44,6 @@ ANDROID)
     ;;
 IOS)
     oslibs="$WORKDIR/UnpackedTarball/icu/source/stubdata/*.a"
-    oslibs="$oslibs $WORKDIR/UnpackedTarball/xmlsec/src/.libs/*.a"
-    oslibs="$oslibs $WORKDIR/UnpackedTarball/xmlsec/src/nss/.libs/*.a"
     ;;
 *)
     oslibs=

external/Module_external.mk

@@ -19,7 +19,7 @@ endif
 
 $(eval $(call gb_Module_add_moduledirs,external,\
 	accessories \
-	libxmlsec \
+	$(if $(filter-out IOS,$(OS)),libxmlsec) \
 	$(call gb_Helper_optional,ABW,libabw) \
 	$(call gb_Helper_optional,APACHE_COMMONS,apache-commons) \
 	$(call gb_Helper_optional,APR,apr) \