wgrib2 should use ${configure.cc}

[ryandesign (Ryan Carsten Schmidt)]

wgrib2 isn't ensuring it's UsingTheRightCompiler.

--->  Building wgrib2
DEBUG: Executing org.macports.build (wgrib2)
DEBUG: port disallows a parallel build
DEBUG: Environment: MACOSX_DEPLOYMENT_TARGET='10.6'
DEBUG: Assembled command: 'cd "/opt/local/var/macports/build/_Users_rschmidt_macports_dports_science_wgrib2/work/grib2/g2clib-1.1.8" && /usr/bin/nice -n 10 /usr/bin/make all -f makefile CPPFLAGS="-I/opt/local/include" CFLAGS="-O2 -arch x86_64 -arch i386"'
cc -c -I/opt/local/include -O2 -arch x86_64 -arch i386 -DUSE_JPEG2000 -DUSE_PNG gridtemplates.c
cc -c -I/opt/local/include -O2 -arch x86_64 -arch i386 -DUSE_JPEG2000 -DUSE_PNG gridtemplates.c
cc: Error: You should be using ${configure.cc}
See http://trac.macports.org/wiki/UsingTheRightCompiler
make: *** [libgrib2c.a(gridtemplates.o)] Error 1

[tenomoto (Takeshi Enomoto)]

Fixed in r63550. Thanks.