Fix incorrect class names of icon font

public/typo3conf/ext/ep_events/Resources/Private/Assets/scss/_fonts.scss

@@ -51,5 +51,5 @@ $font-main: 'Cairo';
 .icon-minus:before { content: '\e801'; }
 .icon-ok:before { content: '\e802'; }
 .icon-calendar:before { content: '\e803'; }
-.icon_mail_circle:before { content: '\e804'; }
-.icon_phone_circle:before { content: '\e805'; }
+.icon-mail-circle:before { content: '\e804'; }
+.icon-phone-circle:before { content: '\e805'; }