Remove user-select: none in theme selector

See https://github.com/FreshRSS/FreshRSS/issues/571

p/themes/base-theme/template.css

@@ -695,14 +695,6 @@ br + br + br {
 	margin-bottom: 30px;
 	border: 1px solid #aaa;
 }
-.slides * {
-	user-select: none;
-	-ms-user-select: none;
-	-moz-user-select: none;
-	-khtml-user-select: none;
-	-webkit-user-select: none;
-	-webkit-touch-callout: none;
-}
 .slides input {
 	display: none;
 }