[enocean] D2-50 EEP remove extra channels and fix warnings

[lovery]

Description

Improvement: Fix 7 warnings on building a jar:

• Null comparison always yields false... - EEPFactory.java:[54,17], EEPFactory.java:[67,17], EnOceanBaseSensorHandler.java:[158,13]
• Dead code (caused by the above warinings) - EEPFactory.java:[54,29], EEPFactory.java:[67,29], EnOceanBaseSensorHandler.java:[158,41]
• Potential null pointer access - EnOceanTransceiver.java:[451,13]

Improvement: remove channels which are not supported by device using EEP D2-50-00, D2-50-01, D2-50-10, D2-50-11. Before this PR choosing either of the above EEP doesn't change anything in the channels list, it looked like all the devices support all channels, but according to the specification they don't. For reference check EnOcean specification on page 236

Test jar file