Update BlockCipher.php

empty($data) returns false when data is 0 (as integer), 0.0 (as float) & '0' (as string). These values should be allowed to get encrypted
test for using logger default errorhandler with streamwriter
[#5383] Remove error handling calls

- The error handling calls pop the scope when already inside an error handler --
  such as when you use the Logger as an error handler. The only call inside the
  block that could be a potential problem is the one to format a DateTime object
  -- and then, only if the format is invalid (in which case you have bigger
  problems).
[#5383] Remove unused use statement
[#5383] Use error suppression *gulp*

- The only viable solution that (a) prevents recursion during serialization, and
  (b) allows the Logger to work as an error handler after a message has been
  formatted, is to use the error suppression operator. See the comment in the
  normalize method for details.
Merge pull request #5383
Merge pull request #5383 in master
Changed validation per @Maks3w suggestion
Merge pull request #5680
Merge pull request #5680 in master
fix cs from #5613
Merge pull request #5899
Merge pull request #5899 in master