fix CFUN restart on R4xxx and add +URAT options

src/TinyGsmClientUBLOX.h

@@ -369,7 +369,14 @@ public:
     if (!testAT()) {
       return false;
     }
-    sendAT(GF("+CFUN=16"));
+    if (!isCatM)
+    {
+      sendAT(GF("+CFUN=16"));
+    }
+    else
+    {
+      sendAT(GF("+CFUN=15"));
+    }
     if (waitResponse(10000L) != 1) {
       return false;
     }
@@ -496,6 +503,24 @@ public:
     else return false;
   }
 
+  bool setURAT( uint8_t urat ) {
+    // AT+URAT=<SelectedAcT>[,<PreferredAct>[,<2ndPreferredAct>]]
+
+    sendAT(GF("+COPS=2"));        // Deregister from network
+    if (waitResponse() != 1) {
+      return false;
+    }
+    sendAT(GF("+CGATT="), urat);  // Radio Access Technology (RAT) selection 
+    if (waitResponse() != 1) {
+      return false;
+    }
+    sendAT(GF("+COPS=0"));        // Auto-register to the network
+    if (waitResponse() != 1) {
+      return false;
+    }
+    return restart();
+  }
+
   /*
    * GPRS functions
    */