core: add missing mouse events "alt-ctrl-button2" and "alt-ctrl-button3"

ChangeLog.adoc

@@ -15,6 +15,7 @@ For a list of important changes that require manual actions, please look at rele
 
 Bug fixes::
 
+  * core: add missing mouse events "alt-ctrl-button2" and "alt-ctrl-button3"
   * script: always display list of scripts when searching scripts with `/script search` (issue #2077)
   * script: fix default mouse keys (issue #2076)
   * trigger: fix memory leak when adding a new trigger with `/trigger` command

src/gui/curses/gui-curses-mouse.c

@@ -74,6 +74,8 @@ char *gui_mouse_button_codes[][2] =
   { "*",  "alt-button2"        },
   { ")",  "alt-button3"        },
   { "8",  "alt-ctrl-button1"   },
+  { ":",  "alt-ctrl-button2"   },
+  { "9",  "alt-ctrl-button3"   },
   { NULL, NULL                 } };