Update VueTabs.js

Fix issue #43

Author: bicienzu

src/components/VueTabs.js

@@ -103,7 +103,10 @@ export default {
         },
         findTabAndActivate (tabNameOrIndex) {
             let indexToActivate = this.tabs.findIndex((tab, index) => tab.title === tabNameOrIndex || index === tabNameOrIndex)
-            if (indexToActivate === this.activeTabIndex) return
+            // if somehow activeTabIndex is not reflected in the actual vue-tab instance, set it.
++           if (indexToActivate === this.activeTabIndex && !this.tabs[this.activeTabIndex].active) {
++              this.tabs[this.activeTabIndex].active = true;
++           }
             if (indexToActivate !== -1) {
                 this.changeTab(this.activeTabIndex, indexToActivate)
             } else {