system-config-keyboard: inherit gettext and add dependency on intltool-native

* it actually depends on native intltool:
  NOTE: recipe system-config-keyboard-1.4.0-r0: task do_compile: Started
  ERROR: system-config-keyboard-1.4.0-r0 do_compile: oe_runmake failed
  ERROR: system-config-keyboard-1.4.0-r0 do_compile: Function failed: do_compile (log file is located at /home/jenkins/oe/world/shr-core/tmp-glibc/work/armv5te-oe-linux-gnueabi/system-config-keyboard/1.4.0-r0/temp/log.do_compile.16052)
  ERROR: Logfile of failure stored in: /home/jenkins/oe/world/shr-core/tmp-glibc/work/armv5te-oe-linux-gnueabi/system-config-keyboard/1.4.0-r0/temp/log.do_compile.16052
  Log data follows:
  | DEBUG: Executing shell function do_compile
  | NOTE: make -j 8 PYTHON=/home/jenkins/oe/world/shr-core/tmp-glibc/sysroots/x86_64-linux/usr/bin/python-native/python PYTHON_SITELIB=/usr/lib/python2.7/site-packages
  | make: intltool-merge: Command not found
  | make: *** [system-config-keyboard.desktop] Error 127
  | ERROR: oe_r...