Handle binding error on initialisation

Author: rastating

payloads/reverse_tcp.rb

@@ -106,7 +106,13 @@ def client_connected(socket, event_emitter)
     def prepare(mod)
       return true unless listen_with_wpxf
 
-      @server = TCPServer.new(bind_to_address, lport)
+      begin
+        @server = TCPServer.new(bind_to_address, lport)
+      rescue StandardError => e
+        mod.emit_error "Failed to start the TCP handler: #{e}"
+        return false
+      end
+
       mod.emit_success "Started reverse TCP handler on #{lport}"
       @network_thread = Thread.new do
         socket = @server.accept