Update WindowsSecurityContextImpl.java to handle SEC_E_BUFFER_TOO_SMALL

[immo7]

Although not documented as a valid return code on MSDN I am now at least the second Waffle user to see a WinError.SEC_E_BUFFER_TOO_SMALL return code in WindowsSecurityContextImpl.initialize. I can confirm that the following patch fixes the problem, but there is no way for a third party to test this because the reason why this seemingly invalid error code is returned and why only to some Windows users is still unknown. The changes themselves are trivial and practically risk-free.
A similar pull request has already been made last year and is still open:
#128 opened on Aug 4, 2014 by kentcb

[dblock]

To be merged this also needs:

• An entry in CHANGELOG.
• The same fix in the C# code, https://github.com/dblock/waffle/search?utf8=%E2%9C%93&q=SEC_E_INSUFFICIENT_MEMORY.
• A confirmation that this actually fixes your problem from the field.

[immo7]

1. Where should I put the entry in CHANGELOG? As part of v1.8.0?
2. I don't have any experience with C#. Those changes should probably better be done by someone else.
3. In what form must I give that confirmation? As proof I can only give you a list of Log Outputs.
   Thanks.

[dblock]

1. Add a Next section, please. It should have been part of the previous release.
2. Well...
3. Make the change, compile the code, run it, confirm that the problem is actually solved.

[hazendaz]

@dblock I'm comfortable with this change as it is very low risk and now we have the fix on both ends. I'll merge othe other shortly.

@immo7 I've merged this on 20ea0b4