fix: PgSQLXML setCharacterStream() results in null value

[davecramer]

fixes Issue #731

[sehrope]

@davecramer Need to add this to a suite for it to run.

Also, s/Copyright (c) 2004/Copyright (c) 2019/.

[davecramer]

@sehrope I knew that and got distracted :( ADD kicking in

[AppVeyorBot]

✅ Build pgjdbc 1.0.514 completed (commit cfe462fa96 by @davecramer)

[sehrope]

@davecramer Well it is a part of the PR checklist template ;-)

[AppVeyorBot]

✅ Build pgjdbc 1.0.515 completed (commit c4130e1c0b by @davecramer)

[davecramer]

@sehrope that's what that's for :)

[codecov-io]

Codecov Report

Merging #1608 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master    #1608      +/-   ##
============================================
+ Coverage     68.96%   68.97%   +<.01%     
+ Complexity     4008     4007       -1     
============================================
  Files           179      179              
  Lines         16654    16655       +1     
  Branches       2714     2714              
============================================
+ Hits          11486    11488       +2     
+ Misses         3911     3908       -3     
- Partials       1257     1259       +2