Fix: regex can't match when proxy was set to some web debugger(e.g. Fiddler) (#553)

Co-authored-by: Umiade <hanyuchao@corp.netease.com>

httplib.h

@@ -4456,7 +4456,7 @@ inline bool Client::read_response_line(Stream &strm, Response &res) {
 
   if (!line_reader.getline()) { return false; }
 
-  const static std::regex re("(HTTP/1\\.[01]) (\\d+?) .*\r\n");
+  const static std::regex re("(HTTP/1\\.[01]) (\\d+).*?\r\n");
 
   std::cmatch m;
   if (std::regex_match(line_reader.ptr(), m, re)) {