fix string-doctags missing from most_similar results
fix string-doctags missing from most_similar results

bug was introduced by changes in #491 / 39b63e0
macks22/gensim,gojomo/gensim,ziky90/gensim,laic/gensim,laic/gensim,piskvorky/gensim,ELind77/gensim,zachmayer/gensim,summanlp/gensim,summanlp/gensim,gojomo/gensim,ziky90/gensim,markroxor/gensim,robotcator/gensim,piskvorky/gensim,davechallis/gensim,mattilyra/gensim,olavurmortensen/gensim,isohyt/gensim,tzoiker/gensim,ELind77/gensim,robotcator/gensim,tzoiker/gensim,isohyt/gensim,RaRe-Technologies/gensim,Kreiswolke/gensim,davechallis/gensim,manasRK/gensim,pombredanne/gensim,zachmayer/gensim,loisaidasam/gensim,mattilyra/gensim,quole/gensim,manasRK/gensim,markroxor/gensim,quole/gensim,jaksmid/gensim,jaksmid/gensim,manasRK/gensim,dsquareindia/gensim,ziky90/gensim,RaRe-Technologies/gensim,ELind77/gensim,robotcator/gensim,macks22/gensim,akutuzov/gensim,dsquareindia/gensim,olavurmortensen/gensim,loisaidasam/gensim,loisaidasam/gensim,mattilyra/gensim,pombredanne/gensim,bhargavvader/gensim,tzoiker/gensim,gojomo/gensim,summanlp/gensim,jaksmid/gensim,Kreiswolke/gensim,zachmayer/gensim,quole/gensim,Kreiswolke/gensim,isohyt/gensim,bhargavvader/gensim,akutuzov/gensim,pombredanne/gensim,dsquareindia/gensim,RaRe-Technologies/gensim,bhargavvader/gensim,laic/gensim,macks22/gensim,akutuzov/gensim,davechallis/gensim,piskvorky/gensim,olavurmortensen/gensim,gojomo/gensim,markroxor/gensim,RaRe-Technologies/gensim