EGO-L-003 warning

signals connected by extension should be disconnected in disable()

Signals assigned in `enable()` are missing matching disconnect calls in `disable()` or its helper methods.

Disconnect all signals

• extension.js:309

  this._graph.connect('repaint', area => this._drawGraph(area))

• extension.js:409

  this._speedButton.connect('clicked', () => this._onSpeedTestClicked())

• extension.js:145

          this.menu.connect('open-state-changed', (_menu, open) => {
              if (open)
                  this._onMenuOpened();
              else
                  this._onMenuClosed();
          })

• extension.js:414

  refreshButton.connect('clicked', () => this._refresh(true))

• extension.js:418

          settingsButton.connect('clicked', () => {
              this._extension.openPreferences();
              this.menu.close();
          })