git-remote-mediawiki: make a regexp clearer

Perl's split function takes a regex pattern argument. You can also
feed it an expression, which is then compiled into a regex at runtime.
It therefore works to pass your pattern via single quotes, but it is
much less obvious to a reader that the argument is meant to be a
regex, not a static string. Using the traditional slash-delimiters
makes this easier to read.

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

@@ -1170,7 +1170,7 @@ sub mw_push_revision {
 		# history (linearized with --first-parent)
 		print STDERR "Warning: no common ancestor, pushing complete history\n";
 		my $history = run_git("rev-list --first-parent --children $local");
-		my @history = split('\n', $history);
+		my @history = split(/\n/, $history);
 		@history = @history[1..$#history];
 		foreach my $line (reverse @history) {
 			my @commit_info_split = split(/ |\n/, $line);