Fixed job OS requirement in the JDL

When a job has the attribute
REQUIRED_OS="any"
the condition GLIDEIN_REQUIRED_OS==REQUIRED_OS in the job requirements expression never matches the job to a glidein at the collector/negotiator because no glidein has
GLIDEIN_REQUIRED_OS="any"
I changed the expresion so that the above comparison is made only when the job has some other value of the attribute like REQUIRED_OS="rhel6". Without the change jobs never run.

The condition on the scramarch when the CondorPlugin sets the REQUIRED_OS="rhel6" requirement in the JDL is also fixed.

We discovered the problem and tested the patch while validating WMagent 0.9.79