308018 only call SendFTPCommand if we haven't been cancelled

r+sr=darin

netwerk/protocol/ftp/src/nsFtpConnectionThread.cpp

@@ -2483,9 +2483,14 @@ void
 nsFtpState::DataConnectionEstablished()
 {
     LOG(("(%x) Data Connection established.", this));
-    
     mWaitingForDConn = PR_FALSE;
 
+    // If we no longer have a channel, we don't need this connection
+    if (!mChannel) {
+        LOG(("    Ignoring data connection"));
+        return;
+    }
+
     // sending empty string with (mWaitingForDConn == PR_FALSE) will cause the 
     // control socket to write out its buffer.
     nsCString a("");