update text format

Author: chinyeungli

README.rst

@@ -177,10 +177,10 @@ the .ABOUT files in the directory /tmp/thirdparty_about/.
                             0 - Do not print any warning or error messages, just a total count (default)
                             1 - Print error messages
                             2 - Print error and warning messages
-    
+
       --template_location=TEMPLATE_LOCATION
                             Use the custom template for the Attribution Generation
-    
+
       --mapping             Configure the mapping key from the MAPPING.CONFIG
 
 Example::