!4 Modify source0 of spec

From: @baizg1107
Reviewed-by: @yanzh_h
Signed-off-by: @yanzh_h

enscript.spec

@@ -1,10 +1,10 @@
 Name:              enscript
 Version:           1.6.6
-Release:           19
+Release:           20
 Summary:           A plain ASCII to PostScript converter
 License:           GPLv3+
 URL:               http://www.gnu.org/software/enscript
-Source0:           enscript-1.6.6.tar.gz
+Source0:           http://ftp.gnu.org/gnu/enscript/enscript-1.6.6.tar.gz
 Source1:           enscript-ruby-1.6.4.tar.gz
 Source2:           enscript-php-1.6.4.st
 BuildRequires:     gcc autoconf automake gettext gettext-devel
@@ -73,5 +73,8 @@ done
 %{_infodir}/enscript*
 
 %changelog
+* Mon Sep 7 2020 baizhonggui<baizhonggui@huawei.com> - 1.6.6-20
+- Modify Source0
+
 * Thu Nov 21 2019 liujing<liujing144@huawei.com> - 1.6.6-19
 - Package init