fix popover padding on bootstrap theme

src/common/common.bootstrap3.css

@@ -12,6 +12,14 @@
 }
 
 
+/* Popover
+--------------------------------------------------------------------------------------------------*/
+
+.fc-bootstrap3 .fc-popover .panel-body {
+	padding: 0; /* undo built-in padding */
+}
+
+
 /* TimeGrid Slats (lines that run horizontally)
 --------------------------------------------------------------------------------------------------*/