Do not write to stderr

fixes open-source-parsers#665
closes open-source-parsers#666

Author: cdunn2001

src/lib_json/json_reader.cpp

@@ -2052,10 +2052,6 @@ JSONCPP_ISTREAM& operator>>(JSONCPP_ISTREAM& sin, Value& root) {
   JSONCPP_STRING errs;
   bool ok = parseFromStream(b, sin, &root, &errs);
   if (!ok) {
-    fprintf(stderr,
-            "Error from reader: %s",
-            errs.c_str());
-
     throwRuntimeError(errs);
   }
   return sin;