patch 8.0.0639: the cursor position is set when editing a new commit message

Problem:    The cursor position is set to the last position in a new commit
            message.
Solution:   Don't set the position if the filetype matches "commit".
            (Christian Brabandt)
diff --git a/src/version.c b/src/version.c
index 00733b3..13dff53 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    639,
+/**/
     638,
 /**/
     637,