Calendar: More sidebox owner fixes

- another instance of remote class causing problems
- remove duplicates to avoid warning message

api/js/etemplate/Et2Select/FindSelectOptions.ts

@@ -267,7 +267,7 @@ export function cleanSelectOptions(options : SelectOption[] | string[] | object)
 			{
 				fixed_options.push(...cleanSelectOptions(option.label));
 			}
-			else
+			else if(fixed_options.findIndex(o => o.value == option.value) == -1)
 			{
 				fixed_options.push(option);
 			}

api/js/etemplate/Et2Select/SearchMixin.ts

@@ -542,6 +542,7 @@ export const Et2WithSearchMixin = <T extends Constructor<LitElement>>(superclass
 				if(options.findIndex(o => o.value == remote.value) != -1)
 				{
 					this._selected_remote.splice(remote_index, 1);
+					this.querySelector('[value="' + remote.value + '"]')?.classList.remove("remote");
 				}
 			}
 		}

calendar/js/app.ts

@@ -3779,7 +3779,7 @@ export class CalendarApp extends EgwApp
 
 		for(const id of Object.keys(event.participants))
 		{
-			if(parseInt(id) >= 0)
+			if(parseInt(id) >= 0 || isNaN(parseInt(id)))
 			{
 				continue;
 			}