BUG: L.U.A. error on custom map pins

[filliph]

Datamine 2.4.6 added tooltip support to Area POI map pins, but doesn't check whether the map pin has poiInfo.

50x Datamine/Modules/Tooltips/Tooltips.lua:910: attempt to index local 'poiInfo' (a nil value)
[Datamine/Modules/Tooltips/Tooltips.lua]:910: in function 'OnTooltipSetAreaPOI'
[Datamine/Modules/Tooltips/Tooltips.lua]:1096: in function <Datamine/Modules/Tooltips/Tooltips.lua:1093>
[Datamine/Modules/Tooltips/Tooltips.lua]:1123: in function <Datamine/Modules/Tooltips/Tooltips.lua:1102>
[C]: ?
[Blizzard_SharedXMLBase/CallbackRegistry.lua]:144: in function <...eBlizzard_SharedXMLBase/CallbackRegistry.lua:143>
[C]: ?
[Blizzard_SharedXMLBase/CallbackRegistry.lua]:147: in function 'TriggerEvent'
[Blizzard_SharedMapDataProviders/SharedMapPoiTemplates.lua]:661: in function <...ard_SharedMapDataProviders/SharedMapPoiTemplates.lua:660>