Images were not loaded, b'couse of getting defined
DBGPLUG_DATA_DIR "${PKGDATADIR}/debugger".

Fixed misspeling for "pludin_datadir"

OS: ArchLinux

the problem is that waf defines DBGPLUG_DATA_DIR as
-DDBGPLUG_DATA_DIR="${PKGDATADIR}/debugger"
instead of :
-DDBGPLUG_DATA_DIR="/usr/local/share/geany-plugins/debugger"

Thanks!