Removed obsolete GMX crawler identifiers/specs from 'crawler.properties' file.

Removed entries:
com.openexchange.subscribe.crawler.gmx=true
com.openexchange.subscribe.crawler.gmx.com=true

Fixed refresh rate property:
com.openexchange.subscribe.crawler.gmx.com.autorun Interval=1d -->
com.openexchange.subscribe.crawler.gmx.de.autorunI nterval=1d