[generator] fixed the skipSql attribute value when exported to XML.
[generator] fixed the skipSql attribute value when exported to XML.

adrianrusnarczyk/Propel,AriaSystems/Propel,tbl0605/Propel-pervasive,propelorm/Propel,Egston/Propel,Innometrics/Propel,propelorm/Propel,PatidarWeb/Propel,PatidarWeb/Propel,gencer/Propel,AriaSystems/Propel,zachmay/Propel,rozwell/Propel,rozwell/Propel,Innometrics/Propel,sh0dow/Propel,adrianrusnarczyk/Propel,halfer/Propel,halfer/Propel,bjdelange/Propel,mhitza/Propel,gencer/Propel,mhitza/Propel,zachmay/Propel,sh0dow/Propel,Egston/Propel,tbl0605/Propel-pervasive,bjdelange/Propel