Fixed printing images from AJAX calls

src/main.py

@@ -122,17 +122,24 @@ def api_print_image():
         sign = request.form["signature"]
     except Exception as e:
         flash(str(e),'error')
-        redirect(url_for('index'))
+        app.logger.error(str(e) + " - Whoops, no forms submitted or missing signature.")
+        return redirect(url_for('index'))
 
     if request.method == 'POST':
         # check if the post request has the file part
-
+        try:
             if 'img' not in request.files:
                 flash('No file found. Did you use the good form ?', 'error')
+                app.logger.error("No file found. Did you use the good form ?")
                 return redirect(url_for("index"))
             else:
                 file = request.files['img']
-
+        except Exception as e:
+            if sign is not None and photo is not None:
+                pass
+            else:
+                flash(str(e), 'error')
+                app.logger.error("Couldn't get an image nor signature : " + str(e))
 
         # If the user does not select a file, the browser submits an
         # empty file without a filename.