0.12-stable: Use the mode "a+" instead of "r+" to check that the PID file is writable, to avoid failing if the file doesn't exist.
0.12-stable: Use the mode "a+" instead of "r+" to check that the PID file is writable, to avoid failing if the file doesn't exist.

Closes #10566.


git-svn-id: 764b04d0c6fbbea0ee05220aef3208173ff13049@11084 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac