Initialize variables in Request and Image.

src/libravatarserv.hpp

@@ -57,7 +57,7 @@ namespace http  // http.cpp
     struct Request
     {
         const string digest;
-        const int16_t size;
+        const int16_t size = 0;
         string fallback;
     };
 
@@ -81,7 +81,7 @@ namespace image // image.cpp
 {
     struct Image
     {
-        uint8_t error;
+        uint8_t error = 0;
         Magick::Image image;
     };