firefox: Remove developer files

/usr/lib/firefox-devel-47.0.1 removed. There are Firefox
Development-Tools.I think, we dont need this directory.
This is 1GB. There is a switch "--disable-developer-tools"
but unfortunately the directory is still there.

firefox.be0

@@ -2,7 +2,7 @@
 
 #export BEE_TMP_TMPDIR=/dev/shm BEE_TMP_BUILDROOT=/dev/shm/bee-root BEE_MAKEFLAGS='-j80'
 
-# BEE_VERSION firefox-47.0.1-1
+# BEE_VERSION firefox-47.0.1-2
 
 SRCURL[0]="https://ftp.mozilla.org/pub/firefox/releases/${PKGVERSION}/source/firefox-${PKGVERSION}.source.tar.xz"
 
@@ -49,6 +49,10 @@ mee_install_post() {
     start_cmd install -d ${D}${LIBDIR}/mariux64
     start_cmd mv ${D}${BINDIR}/${PKGNAME} ${D}${LIBDIR}/mariux64/${PKGNAME}
 
+    # remove unneeded firefox-devel
+
+    rm -r ${D}${LIBDIR}/firefox-devel-${PKGVERSION}
+
     # install official icon in all sizes
 
     for size in 16 22 24 32 48 256 ; do