git-p4 submit: prevent 'Jobs' section from being removed from p4 change log

In an attempt to overwrite the 'Description:' section of the p4 change
log to include the git commit messages, it also overwrote the 'Jobs:'
section.  This fix restores the 'Job:' section.

Signed-off-by: Michael Horowitz <michael.horowitz@ieee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/fast-import/git-p4

@@ -570,7 +570,7 @@ class P4Submit(Command):
                 continue
 
             if inDescriptionSection:
-                if line.startswith("Files:"):
+                if line.startswith("Files:") or line.startswith("Jobs:"):
                     inDescriptionSection = False
                 else:
                     continue