remove unnecessary code

src/bootstrap-table.js

@@ -381,16 +381,6 @@ class BootstrapTable {
       }
     })
 
-    this.$header.children().children().off('keypress').on('keypress', e => {
-      if (this.options.sortable && $(e.currentTarget).data().sortable) {
-        const code = e.keyCode || e.which
-
-        if (code === 13) { // Enter keycode
-          this.onSort(e)
-        }
-      }
-    })
-
     const resizeEvent = Utils.getEventName('resize.bootstrap-table', this.$el.attr('id'))
 
     $(window).off(resizeEvent)