add CSS for .institute-avatar-small/medium, fixes #3540

Closes #3540

Merge request studip/studip!2429

resources/assets/stylesheets/scss/avatar.scss

@@ -62,13 +62,15 @@ div.avatar-widget {
     height: $avatar-normal;
 }
 
-.course-avatar-small {
+.course-avatar-small,
+.institute-avatar-small {
     vertical-align: middle;
     max-width: 25px;
     height: 25px;
 }
 
-.course-avatar-medium {
+.course-avatar-medium,
+.institute-avatar-medium {
     max-width: 180px;
     height: 60px;
 }
@@ -88,7 +90,6 @@ div.avatar-widget {
     width: 60px;
 }
 
-
 #custom_avatar label {
     display: block;
     font-weight: bold;

resources/assets/stylesheets/scss/sidebar.scss

@@ -78,7 +78,7 @@
     }
 
     .course-avatar-medium,
-    .stream-avatar-medium,
+    .institute-avatar-medium,
     .avatar-medium {
         max-width: 60px;
         height: 60px;