Revert "debug print error in case of unexpected login error"

This reverts commit 68d64105de.

src/Security/Login.cpp

@@ -81,7 +81,6 @@ std::string Login(const std::string& fields){
         d.erase("public_key");
         return d.dump();
     }
-    debug(std::string("Backend returned: '") + Buffer + "'")
     return GetFail("Invalid message parsing!");
 }