fix comment

Author: signedav

python/server/auto_generated/qgsserverprojectutils.sip.in

@@ -165,11 +165,11 @@ Returns the maximum number of atlas features which can be printed in a request
 
   double wmsDefaultMapUnitsPerMm( const QgsProject &project );
 %Docstring
-Returns the denominator of the default scale used in case of the scale is not given
+Returns the default number of map units per millimeters in case of the scale is not given
 
 :param project: the QGIS project
 
-:return: the denominator of the scale
+:return: the default number of map units per millimeter
 
 .. versionadded:: 3.8
 %End

src/server/qgsserverprojectutils.h

@@ -155,9 +155,9 @@ namespace QgsServerProjectUtils
   SERVER_EXPORT int wmsMaxAtlasFeatures( const QgsProject &project );
 
   /**
-   * Returns the denominator of the default scale used in case of the scale is not given
+   * Returns the default number of map units per millimeters in case of the scale is not given
    * \param project the QGIS project
-   * \returns the denominator of the scale
+   * \returns the default number of map units per millimeter
    * \since QGIS 3.8
    */
   SERVER_EXPORT double wmsDefaultMapUnitsPerMm( const QgsProject &project );