Small bug in VM menu element tooltip description

[man.of.earth]

In en-GB.com_virtuemart.sys.ini (admin side) the string is
COM_VM_PRODUCTDETAILS_DISPL_CATS_DESCR=...

and in components/com_virtuemart/views/productdetails/tmpl/default.xml is used
COM_VM_PRODUCTDETAILS_DISPL_CATS_DESC (without "R").

The "R" should be removed from the string in the language file, as all the other strings that describe something end in _DESC (and not _DESCR)