www/ls-qpack: fix build on GCC architectures

/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c: In function 'qenc_huffman_enc':
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5028: error: #pragma GCC diagnostic not allowed inside functions
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5029: error: #pragma GCC diagnostic not allowed inside functions
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5030: error: #pragma GCC diagnostic not allowed inside functions
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5126: error: #pragma GCC diagnostic not allowed inside functions
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c: In function 'huff_decode_fast':
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5192: error: #pragma GCC diagnostic not allowed inside functions
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5193: error: #pragma GCC diagnostic not allowed inside functions
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5194: error: #pragma GCC diagnostic not allowed inside functions
/wrkdirs/usr/ports/www/ls-qpack/work/ls-qpack-2.2.1/lsqpack.c:5354: error: #pragma GCC diagnostic not allowed inside functions