Use xmemdupz() in many places.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/connect.c b/connect.c
index 8b1e993..1653a0e 100644
--- a/connect.c
+++ b/connect.c
@@ -393,9 +393,7 @@
 			if (matchlen == 4 &&
 			    !memcmp(value, "none", 4))
 				matchlen = 0;
-			git_proxy_command = xmalloc(matchlen + 1);
-			memcpy(git_proxy_command, value, matchlen);
-			git_proxy_command[matchlen] = 0;
+			git_proxy_command = xmemdupz(value, matchlen);
 		}
 		return 0;
 	}