to get rid of exception that was leftover from debugging

src/json.hpp.re2c

@@ -7940,8 +7940,6 @@ class basic_json
                         ++trailing_zeros;
                     else if((c > '0' and c <= '9') or c == '-')
                         break;
-                    else
-                        throw std::logic_error("unexpected character: "+std::to_string(c));
                 }
                 precision -= (trailing_zeros + 1);
             }