fixed BTM-60: race condition in XAPool.containsXAResourceHolderMatchingGtrid() can throw NPE when trying to recycle a connection
fixed BTM-60: race condition in XAPool.containsXAResourceHolderMatchingGtrid() can throw NPE when trying to recycle a connection

gavioto/btm,leogong/btm,gavioto/btm,Everteam-Software/btm,Everteam-Software/btm,bitronix/btm,veresh/btm,veresh/btm,marcus-nl/btm,brettwooldridge/btm,marcus-nl/btm,tomsorgie/btm,tomsorgie/btm,pgbsl/btm,bitronix/btm,leogong/btm,brettwooldridge/btm,sshankar/btm,pgbsl/btm,sshankar/btm