Fix missing " at the end of first line in GPRS script

it creates the chat config file in
/home/root/Applications/Network/chat/connect-dialup000000000
the first line misses an ending "
then, gprs connection fails and ppp stop after a
chat: missing ending "

src/plugins/network/dialing/config.cpp

@@ -340,7 +340,7 @@ int DialupUI::writeSystemFiles()
 
     // write chat scripts
     QString st;
-    st = "\"\" \"\\K\\K\\K\\d+++ATH\n" // No tr
+    st = "\"\" \"\\K\\K\\K\\d+++ATH\"\n" // No tr
         "ABORT \"NO CARRIER\"\n" // No tr
         "ABORT \"NO DIALTONE\"\n" // No tr
         "ABORT \"BUSY\"\n" // No tr