Possible launching race conditoins

[SijmenHuizenga]

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x429693b2

UE4Editor_AirSim_2712!std::_Tree<std::_Tmap_traits<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::unique_ptr<msr::airlib::AirSimSettings::VehicleSetting,std::default_delete<msr::airlib::AirSimSettings::VehicleSetting> >,std::less<s() [C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.26.28801\INCLUDE\xtree:1708]
UE4Editor_AirSim_2712!msr::airlib::VehicleSimApiBase::getVehicleSetting() [C:\Users\sijme\Formula-Student-Driverless-Simulator\UE4Project\Plugins\AirSim\Source\AirLib\include\api\VehicleSimApiBase.hpp:68]
UE4Editor_AirSim_2712!PawnSimApi::initialize() [C:\Users\sijme\Formula-Student-Driverless-Simulator\UE4Project\Plugins\AirSim\Source\PawnSimApi.cpp:35]
UE4Editor_AirSim_2712!CarPawnSimApi::initialize() [C:\Users\sijme\Formula-Student-Driverless-Simulator\UE4Project\Plugins\AirSim\Source\Vehicles\Car\CarPawnSimApi.cpp:20]
UE4Editor_AirSim_2712!ASimModeCar::createVehicleSimApi() [C:\Users\sijme\Formula-Student-Driverless-Simulator\UE4Project\Plugins\AirSim\Source\Vehicles\Car\SimModeCar.cpp:120]
UE4Editor_AirSim_2712!ASimModeBase::setupVehiclesAndCamera() [C:\Users\sijme\Formula-Student-Driverless-Simulator\UE4Project\Plugins\AirSim\Source\SimMode\SimModeBase.cpp:462]
UE4Editor_AirSim_2712!ASimModeBase::BeginPlay() [C:\Users\sijme\Formula-Student-Driverless-Simulator\UE4Project\Plugins\AirSim\Source\SimMode\SimModeBase.cpp:73]
UE4Editor_AirSim_2712!ASimModeCar::BeginPlay() [C:\Users\sijme\Formula-Student-Driverless-Simulator\UE4Project\Plugins\AirSim\Source\Vehicles\Car\SimModeCar.cpp:17]

Came across this while working on #172 but I don't think it is caused by changes in that pr. Probably some timing / race condition thing.

[SijmenHuizenga]

Maybe it was caused by changes in #172 because after switching back to master I havn't seen this error anymore.