slot name generation bug fix

Author: rubanraj54

src/components/Row.vue

@@ -168,7 +168,7 @@
                 if (has(column,"slot_name")) {
                     return column.slot_name;
                 }
-                return column.name.replace('.','_');
+                return column.name.replace(/\./g,'_');
             }
         },
         computed: {

src/components/VueBootstrap4Table.vue

@@ -840,7 +840,7 @@ export default {
             if (has(column,"slot_name")) {
                 return column.slot_name;
             }
-            return column.name.replace('.','_');
+            return column.name.replace(/\./g,'_');
         },
         // row method ends here
         resetSort() {