Merge branch 'master' into refactor-controller

# Conflicts:
#	src/main/java/mops/gruppen2/controller/WebController.java

src/main/resources/templates/error.html

@@ -27,10 +27,12 @@
             </div>
         </div>
 
-        <button style="color: #52a1eb">
-            <a  style="color: white" class="btn btn-primary btn-lg" href="#" onclick="window.history.back(-1);return false;" role="button">Zurück</a>
+        <button class="btn btn-primary"
+                style="background: #52a1eb; border-style: none;">
+            <a href="#" onclick="window.history.back(-1);return false;" role="button"
+               style="color: white">Zurück</a>
         </button>
     </div>
 </div>
 </body>
-</html>
+</html>