sta_set_eaptls: Don't overwrite identity with "wifi-user@wifilabs.local"

sigma_dut used to overwrite the EAP identity which is being passed by
UCC command with "wifi-user@wifilabs.local" in EAP-TLS authentication.
New authentication servers do not require this static identity and may
fail authentication when it is used. So, don't overwite the identity
with "wifi-user@wifilabs.local" when UCC command includes the
username(identity) parameter.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
diff --git a/sta.c b/sta.c
index efeba50..5b96ef3 100644
--- a/sta.c
+++ b/sta.c
@@ -1384,7 +1384,8 @@
 	if (set_network(ifname, id, "eap", "TLS") < 0)
 		return -2;
 
-	if (set_network_quoted(ifname, id, "identity",
+	if (!get_param(cmd, "username") &&
+	    set_network_quoted(ifname, id, "identity",
 			       "wifi-user@wifilabs.local") < 0)
 		return -2;