mgw, mgcp-li: Handle X-Osmux param name as case insensitive

RFC3435 states most text (except SDP) must be handled as case
insensitive.

Related: OS#4001
Change-Id: Iac073f1db46569b46eddeaecc9934a2986bd50f1
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index 0831abb..74926ad 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -816,7 +816,8 @@
 			mode = (const char *)line + 3;
 			break;
 		case 'X':
-			if (strncmp("Osmux: ", line + 2, strlen("Osmux: ")) == 0) {
+		case 'x':
+			if (strncasecmp("Osmux: ", line + 2, strlen("Osmux: ")) == 0) {
 				/* If osmux is disabled, just skip setting it up */
 				if (!p->endp->cfg->osmux)
 					break;
@@ -1099,7 +1100,8 @@
 			silent = strcmp("noanswer", line + 3) == 0;
 			break;
 		case 'X':
-			if (strncmp("Osmux: ", line + 2, strlen("Osmux: ")) == 0) {
+		case 'x':
+			if (strncasecmp("Osmux: ", line + 2, strlen("Osmux: ")) == 0) {
 				/* If osmux is disabled, just skip setting it up */
 				if (!p->endp->cfg->osmux)
 					break;