Ensure the Escape key doesn't make Plot and Remote docks go away

Override reject() as done in other dock dialogs.

Fixes #1310

src/PlotDock.cpp

@@ -861,3 +861,10 @@ void PlotDock::toggleStackedBars(bool stacked)
     adjustBars();
     ui->plotWidget->replot();
 }
+
+void PlotDock::reject()
+{
+    // We override this, to ensure the Escape key doesn't make this dialog
+    // dock go away
+    return;
+}

src/PlotDock.h

@@ -67,6 +67,7 @@ public slots:
     void updatePlot(SqliteTableModel* model, BrowseDataTableSettings* settings = nullptr, bool update = true, bool keepOrResetSelection = true);
     void fetchAllData();
     void resetPlot();
+    virtual void reject();
 
 signals:
     void pointsSelected(int firstIndex, int count);

src/RemoteDock.cpp

@@ -132,3 +132,10 @@ void RemoteDock::newDirectoryNode(const QModelIndex& parent)
         }
     }
 }
+
+void RemoteDock::reject()
+{
+    // We override this, to ensure the Escape key doesn't make this dialog
+    // dock go away
+    return;
+}

src/RemoteDock.h

@@ -22,6 +22,9 @@ public:
     void reloadSettings();
     void enableButtons();
 
+public slots:
+    virtual void reject();
+
 private slots:
     void setNewIdentity();
     void fetchDatabase(const QModelIndex& idx);