Empty-context add-only patches were applied in the wrong place

[catbref]

Empty-context add-only patches were applied in the wrong place, typically one line early.

Pull-request created in response to request by koppor at:

dnaumenko/java-diff-utils#37

Note: this PR is untested as I simply can't get gradle to work and after an hour of frustration I give up.

[koppor]

@catbref We didn't want to frustrate you :) - We can have a chat on gradle if you want. In IntelliJ, one can simply import the project (choose build.gradle). In the command line, it's just ./gradlew check to run the tests.

I just merge and check whether travis likes your changes. 😇

[koppor]

Runs fine --> https://travis-ci.org/java-diff-utils/java-diff-utils/builds/396991134.

Thank you for the PR!

Note that there is another variant (with more stars) at https://github.com/wumpz/java-diff-utils. The code seems to be very different from this. I haven't tried out it. My current aim is to get a release ready which can be included in debian. In parallel, I'm trying to contact @wumpz to join forces and to get a unified library out of it - with a clear license.

Refs java-diff-utils/java-diff-utils#9