Fix detection of the "command" command line argument. Fixes #351.
Fix detection of the "command" command line argument. Fixes #351.

alexeibs/dub,jelmansouri/dub,Geod24/dub,dreamsxin/dub,y12uc231/dub,Flamaros/dub,Abscissa/dub,p0nce/dub,gedaiu/dub,Abscissa/dub-data-mod,nazriel/dub,schuetzm/dub,xentec/dub,jeanbaptistelab/dub,grogancolin/dub,rjframe/dub,D-Programming-Language/dub