Drop reference to non existing part.

component/gcc/buildout.cfg

@@ -128,7 +128,7 @@ configure-options =
   --prefix=${buildout:parts-directory}/${:_buildout_section_name_}
 
 environment =
-  LDFLAGS=-Wl,-rpath=${mpfr:location}/lib -Wl,-rpath=${gmp:location}/lib -Wl,-rpath=${mpc:location}/lib -Wl,-rpath=${ppl:location}/lib -Wl,-rpath=${cloog-ppl:location}/lib -Wl,-rpath=${libelf:location}/lib
+  LDFLAGS=-Wl,-rpath=${mpfr:location}/lib -Wl,-rpath=${gmp:location}/lib -Wl,-rpath=${mpc:location}/lib -Wl,-rpath=${ppl:location}/lib -Wl,-rpath=${cloog-ppl:location}/lib
   PATH=${zip:location}/bin:%(PATH)s
 # make install does not work when several core are used
 make-targets = install -j1