Fix some display bugs in expose on chrome

Sometimes the picture didn't get shown right away

api/js/etemplate/Expose/ExposeMixin.ts

@@ -855,7 +855,7 @@ export function ExposeMixin<B extends Constructor<LitElement>>(superclass : B)
 		{
 			// Check to see if we're in a nextmatch, do magic
 			let nm = this.find_nextmatch(this);
-			if(nm)
+			if(nm && !nm.update_in_progress)
 			{
 				// Check to see if we're near the end, or maybe some pagination
 				// would be good.

api/templates/default/etemplate2.css

@@ -3496,6 +3496,9 @@ span.et2_egw_action_ddHelper_itemsCnt {
 /**
  * Etemplate exposé CSS
  */
+.blueimp-gallery > .slides > .slide-prev, .blueimp-gallery > .slides > .slide.active, .blueimp-gallery > .slides > .slide-next {
+    visibility: visible;
+}
 /* Paginating with nextmatch */
 .blueimp-gallery-controls > .indicator.paginating {
     border-bottom: 2px solid rgba(255, 255, 255, 0.5);