Fixed empty configure block for older versions of autoconf.
Fixed empty configure block for older versions of autoconf.

surround-io/oclgrind,bitfusionio/Oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind,bitfusionio/Oclgrind,surround-io/oclgrind,mpflanzer/Oclgrind,bitfusionio/Oclgrind,bitfusionio/Oclgrind,mpflanzer/Oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind