BinaryJedis.multi(TransactionBlock) should not call discard when exception occurred

* In BinaryJedis.multi(TransactionBlock), multi & exec already fired before exception occured, so sending discard has no effect, and made another error
** add unit test (error inside TransactionBlock)
*** Transaction with error - Redis discards transaction automatically (execabort)
*** Transaction with error - Redis doesn't roll back (force to execute all)
Merge branch 'transaction-block-should-not-call-discard-when-exception-ocurred' of github.com:HeartSaVioR/jedis into HeartSaVioR-transaction-block-should-not-call-discard-when-exception-ocurred

Conflicts:
	src/test/java/redis/clients/jedis/tests/commands/TransactionCommandsTest.java