Align the same equation and the same size in 5.7.1.5 and A.3.6

Author: ocampana-videotec

doc/PTZ.xml

@@ -2439,7 +2439,7 @@ tns1:PTZController/PTZPresets/Left
         <para>
           <mediaobject>
             <imageobject>
-              <imagedata fileref="equations/Ptz/normalized_digital_zoom_factor.svg" contentdepth="8mm" align="center"/>
+              <imagedata fileref="equations/Ptz/normalized_digital_zoom_factor.svg" contentdepth="9mm" align="center"/>
             </imageobject>
           </mediaobject>
         </para>