Generate cpp project Couldn't find UnrealBuildTool

I spend about half a day fighting this bug. This is of course also due to my lack of experience with UE. But once clean didn’t work anymore (without me noticing), my changes in that one cpp-file were not reflected in the engine anymore. Naturally, I didn’t realize that, either. Instead I added log statement of all kinds and got frustrated that no log would show up and so on and so forth. Thanks for that fix!