fixed GraphEdit signal argument type

doc/classes/GraphEdit.xml

@@ -285,7 +285,7 @@
 		</signal>
 		<signal name="connection_drag_started">
 			<param index="0" name="from" type="String" />
-			<param index="1" name="slot" type="String" />
+			<param index="1" name="slot" type="int" />
 			<param index="2" name="is_output" type="bool" />
 			<description>
 				Emitted at the beginning of a connection drag.

scene/gui/graph_edit.cpp

@@ -2381,7 +2381,7 @@ void GraphEdit::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("begin_node_move"));
 	ADD_SIGNAL(MethodInfo("end_node_move"));
 	ADD_SIGNAL(MethodInfo("scroll_offset_changed", PropertyInfo(Variant::VECTOR2, "offset")));
-	ADD_SIGNAL(MethodInfo("connection_drag_started", PropertyInfo(Variant::STRING, "from"), PropertyInfo(Variant::STRING, "slot"), PropertyInfo(Variant::BOOL, "is_output")));
+	ADD_SIGNAL(MethodInfo("connection_drag_started", PropertyInfo(Variant::STRING, "from"), PropertyInfo(Variant::INT, "slot"), PropertyInfo(Variant::BOOL, "is_output")));
 	ADD_SIGNAL(MethodInfo("connection_drag_ended"));
 
 	BIND_ENUM_CONSTANT(SCROLL_ZOOMS);