force autofocus in rename-tab modal (fixes #484)

terminus-core/src/components/renameTabModal.component.pug

 .modal-body
-    input.form-control(type='text', [(ngModel)]='value', (keyup.enter)='save()', autofocus)
+    input.form-control(type='text', #input, [(ngModel)]='value', (keyup.enter)='save()', autofocus)
 
 .modal-footer
     button.btn.btn-outline-primary((click)='save()') Save

terminus-core/src/components/renameTabModal.component.ts

-import { Component, Input } from '@angular/core'
+import { Component, Input, ElementRef } from '@angular/core'
 import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
 
 @Component({
@@ -7,11 +7,18 @@ import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
 })
 export class RenameTabModalComponent {
     @Input() value: string
+    @ViewChild('input') input: ElementRef
 
     constructor (
         private modalInstance: NgbActiveModal
     ) { }
 
+    ngOnInit () {
+        setTimeout(() => {
+            this.input.nativeElement.focus()
+        })
+    }
+
     save () {
         this.modalInstance.close(this.value)
     }