Disable readline's SIGWINCH handler

We no longer need it as we handle SIGWINCH ourselves.  Also move the
call to init_page_info() from initialize_utils() to the latter
function's only caller, gdb_init().

gdb/ChangeLog:

	* utils.c (init_page_info): Set rl_catch_sigwinch to zero.
	(initialize_utils): Move call of init_page_info() to ...
	* top.c (gdb_init): ... here.

gdb/utils.c

@@ -1696,6 +1696,9 @@ init_page_info (void)
 #endif
     }
 
+  /* We handle SIGWINCH ourselves.  */
+  rl_catch_sigwinch = 0;
+
   set_screen_size ();
   set_width ();
 }
@@ -2712,8 +2715,6 @@ Setting this to \"unlimited\" or zero causes GDB never pause during output."),
 			    show_lines_per_page,
 			    &setlist, &showlist);
 
-  init_page_info ();
-
   add_setshow_boolean_cmd ("pagination", class_support,
 			   &pagination_enabled, _("\
 Set state of GDB output pagination."), _("\