Remove unused dependency.

src/operations/operationEditModal.component.ts

@@ -1,6 +1,5 @@
 // vim: set tw=80 ts=2 sw=2 sts=2:
 import { Component, Input } from '@angular/core';
-import { NgForm } from '@angular/forms';
 
 import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap';