unused example ID causes entire file to be shown

[sav-norem]

xadd_7 is a redis 7 feature and had not yet been implemented - will update when it is but currently it leads to unexpected behavior on the website to have it missing

[dwdougherty]

@sav-norem I noticed that return value variable numbering is off between Java and Python, and I think it's because there is no "res*" variable/value for the missing example, the one this PR addresses. I don't know that it's a big deal, but you might increment all the "res*" variables following the placeholder example. The missing example would be "res11" and the next one (xrange) would be "res12", etc.