gschem: Workaround for zero-height text view bug.

This is a temporary workaround for a bug on systems using overlay
scrollbars for GTK+ widgets, where the value editing GtkTextView in
the multi-attribute editing dialog was appearing with zero height.

Obviously, setting the height request to a constant size isn't ideal.
It would be better to set the height request based on the font size,
so that a certain number of lines are displayed.

This should be revisited at a later date.

Affects-bug: lp-876299

gschem/src/x_multiattrib.c

@@ -2001,7 +2001,10 @@ static void multiattrib_init(Multiattrib *multiattrib)
 					   "shadow-type",
 					   GTK_SHADOW_IN,
 					   NULL));
+  /*! \fixme Forcing the size request is a horrible band-aid and
+   *  should be replaced by a better heuristic. */
   textview = GTK_WIDGET (g_object_new (GTK_TYPE_TEXT_VIEW,
+                                       "height-request", 50,
 				       NULL));
   g_signal_connect (textview,
 		    "key_press_event",