add gcc as BR

addressing:
gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -fPIC -I/usr/include/python2.7 -c procnamemodule.c -o build/temp.linux-x86_64-2.7/procnamemodule.o
unable to execute gcc: No such file or directory
error: command 'gcc' failed with exit status 1
error: Bad exit status from /var/tmp/rpm-tmp.qEr7wX (%build)
remove procname and use setproctitle instead