git-remote-mediawiki: move a variable declaration at the top of the code

%basetimestamps declaration was lost in the middle of subroutines

Signed-off-by: Célestin Matte <celestin.matte@ensimag.fr>
Signed-off-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/mw-to-git/git-remote-mediawiki.perl

@@ -91,6 +91,9 @@
 	$fetch_strategy = "by_page";
 }
 
+# Remember the timestamp corresponding to a revision id.
+my %basetimestamps;
+
 # Dumb push: don't update notes and mediawiki ref to reflect the last push.
 #
 # Configurable with mediawiki.dumbPush, or per-remote with
@@ -480,9 +483,6 @@ sub get_last_local_revision {
 	return $lastrevision_number;
 }
 
-# Remember the timestamp corresponding to a revision id.
-my %basetimestamps;
-
 # Get the last remote revision without taking in account which pages are
 # tracked or not. This function makes a single request to the wiki thus
 # avoid a loop onto all tracked pages. This is useful for the fetch-by-rev