Revert: Make string to double conversion locale invariant.

It appears this actually is not necessary in JsonCpp 1.9.5 (see CommonCpp test: "JsonReader_WithDoubleValueAndDiffLocales_ReturnsNumberWithDecimalPart")

Author: mike-malburg

src/lib_json/json_reader.cpp

@@ -601,7 +601,6 @@ bool Reader::decodeDouble(Token& token, Value& decoded) {
   double value = 0;
   String buffer(token.start_, token.end_);
   IStringStream is(buffer);
-  is.imbue(std::locale::classic());
   if (!(is >> value)) {
     if (value == std::numeric_limits<double>::max())
       value = std::numeric_limits<double>::infinity();