Add new line in appendDiffValue

so that it's only added when needed (i.e. when there are a diff value).

android_app/app/src/main/java/com/health/openscale/gui/fragments/TableFragment.java

@@ -494,7 +494,6 @@ public class TableFragment extends Fragment implements FragmentUpdateListener {
 
                     SpannableStringBuilder string = new SpannableStringBuilder();
                     string.append(visibleMeasurements.get(i).getValueAsString());
-                    string.append("\n");
                     visibleMeasurements.get(i).appendDiffValue(string);
 
                     stringCache[position][i] = string;

android_app/app/src/main/java/com/health/openscale/gui/views/FloatMeasurementView.java

@@ -286,6 +286,7 @@ public abstract class FloatMeasurementView extends MeasurementView {
             color = Color.GRAY;
         }
 
+        text.append('\n');
         int start = text.length();
         text.append(symbol);
         text.setSpan(new ForegroundColorSpan(color), start, text.length(),