Update build.xml
Update build.xml

A '=' sign was missing in the comment which makes a little confusion for beginners.
puravidaapps/appinventor-sources,kkashi01/appinventor-sources,barreeeiroo/appinventor-sources,mit-cml/appinventor-sources,halatmit/appinventor-sources,marksherman/appinventor-sources,josmas/app-inventor,halatmit/appinventor-sources,kkashi01/appinventor-sources,josmas/app-inventor,jisqyv/appinventor-sources,kkashi01/appinventor-sources,kkashi01/appinventor-sources,puravidaapps/appinventor-sources,jisqyv/appinventor-sources,mit-cml/appinventor-sources,puravidaapps/appinventor-sources,barreeeiroo/appinventor-sources,mit-cml/appinventor-sources,marksherman/appinventor-sources,josmas/app-inventor,puravidaapps/appinventor-sources,halatmit/appinventor-sources,jisqyv/appinventor-sources,marksherman/appinventor-sources,mit-cml/appinventor-sources,jisqyv/appinventor-sources,josmas/app-inventor,barreeeiroo/appinventor-sources,kkashi01/appinventor-sources,jisqyv/appinventor-sources,ewpatton/appinventor-sources,mit-dig/punya,halatmit/appinventor-sources,mit-dig/punya,mit-dig/punya,mit-dig/punya,marksherman/appinventor-sources,marksherman/appinventor-sources,halatmit/appinventor-sources,mit-dig/punya,barreeeiroo/appinventor-sources,ewpatton/appinventor-sources,ewpatton/appinventor-sources,kkashi01/appinventor-sources,mit-dig/punya,ewpatton/appinventor-sources,mit-cml/appinventor-sources,halatmit/appinventor-sources,ewpatton/appinventor-sources,ewpatton/appinventor-sources,mit-dig/punya,josmas/app-inventor,puravidaapps/appinventor-sources,marksherman/appinventor-sources,jisqyv/appinventor-sources,josmas/app-inventor,barreeeiroo/appinventor-sources,mit-cml/appinventor-sources