fix PFS when the number of items in main grid is smaller than anchoring genome
fix PFS when the number of items in main grid is smaller than anchoring genome

nconrad/p3_web,hyoo/p3_web,zreyn/p3_web,maovt/p3_web,zreyn/p3_web,PATRIC3/p3_web,dmachi/p3_web,nconrad/p3_web,zreyn/p3_web,dmachi/p3_web,aswarren/p3_web,dmachi/p3_web,PATRIC3/p3_web,PATRIC3/p3_web,hyoo/p3_web,PATRIC3/p3_web,maovt/p3_web,dawenx/p3_web,maovt/p3_web,dawenx/p3_web,dawenx/p3_web,nconrad/p3_web,zreyn/p3_web,dmachi/p3_web,nconrad/p3_web,aswarren/p3_web,hyoo/p3_web,maovt/p3_web,aswarren/p3_web,hyoo/p3_web,dawenx/p3_web,aswarren/p3_web