Login: Use static background image

public/css/icinga/login.less

@@ -5,10 +5,11 @@
 #login {
 
   height: 100%;
-  background-color: @icinga-secondary;
+  background-color: @menu-bg-color;
   background-repeat:  no-repeat;
   background-position: center center;
-  //background-image: url(../img/icingaweb2-background.jpg);
+  background-image: url(../img/icingaweb2-background-orbs.jpg);
+
   // fallback ie 9
   background-size: 100% 100%;
   background-size: cover;
@@ -24,7 +25,7 @@
 
   .login-form {
     position: relative;
-    background: @menu-bg-color;
+    background: @body-bg-color;
     min-width: 288px;
     height: 100%;
     width: 33%;