fix v1.78 enum popup on xeh incompatible objects by fallback loop

[commy2]

When merged this pull request will:

• Adding events that don't exist doesn't matter, except that it does now by creating that enum error. This PR makes it so we don't.

[commy2]

16:59:26 Error in expression <f (!isClass _eventClass) then {
{
_unit addEventHandler [_x, format ['call cba_x>
16:59:26   Error position: <addEventHandler [_x, format ['call cba_x>
16:59:26   Error Foreign error: Unknown enum value: "FiredBis"
16:59:26 File \x\cba\addons\xeh\fnc_initEvents.sqf [CBA_fnc_initEvents], line 1946
16:59:26 Error in expression <f (!isClass _eventClass) then {
{
_unit addEventHandler [_x, format ['call cba_x>
16:59:26   Error position: <addEventHandler [_x, format ['call cba_x>
16:59:26   Error Foreign error: Unknown enum value: "InitPost"
16:59:26 File \x\cba\addons\xeh\fnc_initEvents.sqf [CBA_fnc_initEvents], line 1946