i18n: format_tracking_info "Your branch is behind" message

Function format_tracking_info in remote.c is called by
wt_status_print_tracking in wt-status.c, which will print
branch tracking message in git-status. git-checkout also
show these messages through it's report_tracking function.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

remote.c

@@ -1572,19 +1572,29 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
 	base = branch->merge[0]->dst;
 	base = shorten_unambiguous_ref(base, 0);
 	if (!num_theirs)
-		strbuf_addf(sb, "Your branch is ahead of '%s' "
-			    "by %d commit%s.\n",
-			    base, num_ours, (num_ours == 1) ? "" : "s");
+		strbuf_addf(sb,
+			Q_("Your branch is ahead of '%s' by %d commit.\n",
+			   "Your branch is ahead of '%s' by %d commits.\n",
+			   num_ours),
+			base, num_ours);
 	else if (!num_ours)
-		strbuf_addf(sb, "Your branch is behind '%s' "
-			    "by %d commit%s, "
-			    "and can be fast-forwarded.\n",
-			    base, num_theirs, (num_theirs == 1) ? "" : "s");
+		strbuf_addf(sb,
+			Q_("Your branch is behind '%s' by %d commit, "
+			       "and can be fast-forwarded.\n",
+			   "Your branch is behind '%s' by %d commits, "
+			       "and can be fast-forwarded.\n",
+			   num_theirs),
+			base, num_theirs);
 	else
-		strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
-			    "and have %d and %d different commit(s) each, "
-			    "respectively.\n",
-			    base, num_ours, num_theirs);
+		strbuf_addf(sb,
+			Q_("Your branch and '%s' have diverged,\n"
+			       "and have %d and %d different commit each, "
+			       "respectively.\n",
+			   "Your branch and '%s' have diverged,\n"
+			       "and have %d and %d different commits each, "
+			       "respectively.\n",
+			   num_theirs),
+			base, num_ours, num_theirs);
 	return 1;
 }