if AsyncLoad parameter is None, do not try to open it, and Async returns None
if AsyncLoad parameter is None, do not try to open it, and Async returns None

This fixes a bug with LCL for transactions without details

sputnick-dev/weboob,sputnick-dev/weboob,nojhan/weboob-devel,willprice/weboob,willprice/weboob,RouxRC/weboob,laurent-george/weboob,nojhan/weboob-devel,nojhan/weboob-devel,RouxRC/weboob,sputnick-dev/weboob,RouxRC/weboob,laurent-george/weboob,laurent-george/weboob,willprice/weboob