core: add another CnS string to the immediate ignore list

Newer Sierra devices have this (ie 306); it's the CnS port so ignore
it immediately.

src/mm-plugin-base.c

@@ -511,6 +511,7 @@ static const char *dq_strings[] = {
     "os_logids.h",
     /* Sierra CnS port */
     "NETWORK SERVICE CHANGE",
+    "/SRC/AMSS",
     NULL
 };