rename yAxisScale to axisScale

For some reason PlotRequest.yAxisScale does
not work. PlotRequest.axisScale does work.

pdb-ui/src/main/java/org/lucares/pdbui/domain/PlotRequest.java

@@ -115,11 +115,11 @@ public class PlotRequest {
 		this.dateRange = dateRange;
 	}
 
-	public AxisScale getYAxisScale() {
+	public AxisScale getAxisScale() {
 		return yAxisScale;
 	}
 
-	public void setYAxisScale(final AxisScale yAxis) {
+	public void setAxisScale(final AxisScale yAxis) {
 		this.yAxisScale = yAxis;
 	}