patch 8.1.0133: tagfiles() can have duplicate entries

Problem:    tagfiles() can have duplicate entries.
Solution:   Simplify the filename to make checking for duplicates work better.
            Add a test. (Dominique Pelle, closes #2979)
diff --git a/src/version.c b/src/version.c
index 572b8f1..c724159 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    133,
+/**/
     132,
 /**/
     131,