Fix usage documentation mentioning nohelp default value

Author: indyteo

src/site/apt/usage.apt.vm

@@ -148,7 +148,7 @@ mvn javadoc:test-aggregate-jar
 
  [<<<mvn site>>>] It will generate the Javadoc for public members (defined in \<reporting/\>) using the given
  stylesheet (defined in \<reporting/\>), and with a help page (default value for
- {{{./javadoc-mojo.html#nohelp}nohelp}} is true).
+ {{{./javadoc-mojo.html#nohelp}nohelp}} is false).
 
  [<<<mvn javadoc:javadoc>>>] It will generate the Javadoc for private members (defined in \<build/\>) using the
  stylesheet (defined in \<reporting/\>), and with no help page (defined in \<build/\>).