Adding caching to profile images to master (#5428)

* Adding caching to profile images

* Fixing break

* Adding back in failed read

* Fixing build break

* Fixing break

app/user.go

@@ -667,25 +667,28 @@ func CreateProfileImage(username string, userId string) ([]byte, *model.AppError
 	}
 }
 
-func GetProfileImage(user *model.User) ([]byte, *model.AppError) {
+func GetProfileImage(user *model.User) ([]byte, bool, *model.AppError) {
 	var img []byte
+	readFailed := false
 
 	if len(utils.Cfg.FileSettings.DriverName) == 0 {
 		var err *model.AppError
 		if img, err = CreateProfileImage(user.Username, user.Id); err != nil {
-			return nil, err
+			return nil, false, err
 		}
 	} else {
 		path := "users/" + user.Id + "/profile.png"
 
 		if data, err := ReadFile(path); err != nil {
+			readFailed = true
+
 			if img, err = CreateProfileImage(user.Username, user.Id); err != nil {
-				return nil, err
+				return nil, false, err
 			}
 
 			if user.LastPictureUpdate == 0 {
 				if err := WriteFile(img, path); err != nil {
-					return nil, err
+					return nil, false, err
 				}
 			}
 
@@ -694,7 +697,7 @@ func GetProfileImage(user *model.User) ([]byte, *model.AppError) {
 		}
 	}
 
-	return img, nil
+	return img, readFailed, nil
 }
 
 func SetProfileImage(userId string, imageData *multipart.FileHeader) *model.AppError {