Preferences > SQL: Avoid different heights due to having check boxes or not

The uniform row heights property is set so the rows without check boxes is
the same as the rows with them (the difference might only be observable
with some theme engines)

src/PreferencesDialog.cpp

@@ -40,6 +40,9 @@ PreferencesDialog::PreferencesDialog(QWidget* parent)
 #endif
 
     loadSettings();
+
+    // Avoid different heights due to having check boxes or not
+    ui->treeSyntaxHighlighting->setUniformRowHeights(true);
 }
 
 /*