Trigger autocompletion when the input field is focused

This unifies the behaviour with the one used in the file list, and it
will also simplify other changes in following commits (like not needing
to show error messages when confirming a share and instead rely on those
from the autocompletion).

Signed-off-by: Daniel Calviño Sánchez <[email protected]>

js/vendor/nextcloud/share.js

@@ -578,6 +578,11 @@
 					}
 				});
 
+				/* trigger search after the field was re-selected */
+				$('#shareWith').on('focus', function() {
+					$(this).autocomplete('search');
+				});
+
 				if (link && linksAllowed && $('#email').length != 0) {
 					$('#email').autocomplete({
 						minLength: 1,