OpenTopoMap max zoom on fallback server only z15, fixes #21;  also fix max zoom for other services to actual
OpenTopoMap max zoom on fallback server only z15, fixes #21; 
also fix max zoom for other services to actual
bstegmaier/brouter-web,nrenner/brouter-web,nrenner/brouter-web,bstegmaier/brouter-web,nrenner/brouter-web,RoPP/brouter-web,saesh/brouter-web,RoPP/brouter-web,saesh/brouter-web,saesh/brouter-web