gpg4libre: package gpgme spawn helper for Windows

Change-Id: If8dbe10b87d329fab3639392f6c352bce75c54c1
Reviewed-on: https://gerrit.libreoffice.org/45127Reviewed-by: Siegmund Gorr <siegmund.gorr@cib.de>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Tested-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

RepositoryExternal.mk

@@ -3534,6 +3534,10 @@ $(eval $(call gb_Helper_register_libraries_for_install,PLAINLIBS_OOO,ooo,\
 	gpgmepp \
 ))
 
+$(eval $(call gb_Helper_register_executables_for_install,OOO,ooo, \
+	gpgmepp-w32spawn \
+))
+
 endif
 
 ifneq ($(filter MACOSX LINUX,$(OS)),)