Fix url

Author: ax3l

src/Error.cpp

@@ -49,8 +49,8 @@ namespace error
     Internal::Internal(std::string const &what)
         : Error(
               "Internal error: " + what +
-              "\nThis is a bug. Please report at ' "
-              "https://github.com/openPMD/openPMD-api/issues'.")
+              "\nThis is a bug. Please report at "
+              "https://github.com/openPMD/openPMD-api/issues")
     {}
 } // namespace error
 } // namespace openPMD