credential-osxkeychain: support more protocols

Add protocol imap, imaps, ftp and smtp for credential-osxkeychain.
Signed-off-by: NXidorn Quan <quanxunzhen@gmail.com>
Acked-by: NJohn Szakmeister <john@szakmeister.net>
Acked-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

contrib/credential/osxkeychain/git-credential-osxkeychain.c

@@ -127,10 +127,20 @@ static void read_credential(void)
 		*v++ = '\0';
 
 		if (!strcmp(buf, "protocol")) {
-			if (!strcmp(v, "https"))
+			if (!strcmp(v, "imap"))
+				protocol = kSecProtocolTypeIMAP;
+			else if (!strcmp(v, "imaps"))
+				protocol = kSecProtocolTypeIMAPS;
+			else if (!strcmp(v, "ftp"))
+				protocol = kSecProtocolTypeFTP;
+			else if (!strcmp(v, "ftps"))
+				protocol = kSecProtocolTypeFTPS;
+			else if (!strcmp(v, "https"))
 				protocol = kSecProtocolTypeHTTPS;
 			else if (!strcmp(v, "http"))
 				protocol = kSecProtocolTypeHTTP;
+			else if (!strcmp(v, "smtp"))
+				protocol = kSecProtocolTypeSMTP;
 			else /* we don't yet handle other protocols */
 				exit(0);
 		}