make fred's sound environment dropdown a full list (scp-fs2open#7303)

Author: MjnMixael

fred2/fred.rc

@@ -2348,7 +2348,7 @@ STYLE DS_SETFONT | DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
 CAPTION "Sound Environment"
 FONT 8, "MS Sans Serif", 0, 0, 0x1
 BEGIN
-    COMBOBOX        IDC_SOUND_ENVIRONMENT,75,9,117,30,CBS_DROPDOWN | WS_VSCROLL | WS_TABSTOP
+    COMBOBOX        IDC_SOUND_ENVIRONMENT,75,9,117,120,CBS_DROPDOWNLIST | WS_VSCROLL | WS_TABSTOP
     EDITTEXT        IDC_SOUND_ENVIRONMENT_VOLUME,75,31,76,12,ES_AUTOHSCROLL
     EDITTEXT        IDC_SOUND_ENVIRONMENT_DAMPING,75,48,76,12,ES_AUTOHSCROLL
     EDITTEXT        IDC_SOUND_ENVIRONMENT_DECAY,75,64,76,12,ES_AUTOHSCROLL