Fixed snowball_ext/Makefile to correct generation of SQL file on Windows

Author: dmpgpro

contrib/snowball_ext/Makefile

@@ -39,7 +39,7 @@ LANGUAGES=  \
 
 all: $(SQLSCRIPT);
 
-$(SQLSCRIPT): Makefile snowball_ext_func.sql.in snowball_ext.sql.in
+$(SQLSCRIPT): snowball_ext_func.sql.in snowball_ext.sql.in
 	echo '-- Language-specific snowball dictionaries' > $@
 	cat $(srcdir)/snowball_ext_func.sql.in >> $@
 	@set -e; \