Fix: Bootstrap 4 flexbox grid

The flexbox enabled grid in bootstap 4 requires the lowest `.col-` to be set. twbs/bootstrap#17603 (comment)

Sync to source repo @014cb111b8284f61d832ac3b6b5f868cbbc08fa5

Author: AllanJard

datatables.json

@@ -5,6 +5,6 @@
         "js/jquery.dataTables.min.js"
     ],
     "src-repo": "http://github.com/DataTables/DataTablesSrc",
-    "last-sync": "d767a822a63d7c1f68cd487478890a2312282bac",
+    "last-sync": "014cb111b8284f61d832ac3b6b5f868cbbc08fa5",
     "last-tag": "1.10.12"
 }