adjust styles for overlay of Editor

src/client/styles/scss/_editor-attachment.scss

@@ -14,7 +14,7 @@
 
     position: relative;   // against .overlay position: absolute
 
-    @include overlay-processing-style(overlay-dropzone-active, 2.5em);
+    @include overlay-processing-style(overlay-dropzone-active, 2.5em, 0.5em);
 
     // unuploadable or rejected
     &.dropzone-unuploadable, &.dropzone-rejected {
@@ -28,7 +28,7 @@
     }
     // uploading
     &.dropzone-uploading {
-      @include overlay-processing-style(overlay-dropzone-active, 2.5em);
+      @include overlay-processing-style(overlay-dropzone-active, 2.5em, 0.5em);
     }
 
     // unuploadable

src/client/styles/scss/_editor-overlay.scss

@@ -23,11 +23,6 @@
     right: 0;
     bottom: 0;
     left: 0;
-    .overlay-content {
-      padding: 0.5em;
-      right: 0;
-      bottom: 0;
-    }
   }
 
   // loading keymap