Update main.cpp

16:44:13: ERROR[main]: ERROR: An unhandled exception occurred: error in error handling

In thread 7f6bae637740:
/home/sebastian/minetest/minetest-minetest-eec456b/src/main.cpp:1945: int main(int, char**): Assertion '0' failed.
Debug stacks:
DEBUG STACK FOR THREAD 7f6ba6cd3700:
#0  virtual void* CurlFetchThread::Thread()
DEBUG STACK FOR THREAD 7f6bae637740:
#0  int main(int, char**)
(Leftover data: #1  Dedicated server branch)
(Leftover data: #2  virtual void ServerMap::save(ModifiedState))
(Leftover data: #3  void ItemStack::serialize(std::ostream&) const)
Abgebrochen (Speicherabzug geschrieben)