fix: regression by reverting fix that returned 206 when first-pos=length in Range header #2115

Loadtest Results

param	v11.2.1	head	main
bytes_in.mean	1030.3944375333215	1030.4836112708454	1030.4063092038596
bytes_in.total	23192118	23296143	23387132
bytes_out.mean	3848.2943842189443	3848.29588180652	3847.961316473543
bytes_out.total	86617410	86998425	87337178
duration	60015788662	60003622284	60000904995
errors.0	400 Bad Request	400 Bad Request	400 Bad Request
latencies.50th	1031851	1038251	1034128
latencies.90th	3329468	2884108	2935553
latencies.95th	18107903	17949342	17864065
latencies.99th	18638562	18465123	18412135
latencies.max	39043594	40035205	31955786
latencies.mean	2665090	2652869	2642195
latencies.min	152500	166206	162700
latencies.total	59985848011	59973414296	59969917339
rate	375.0346450791759	376.7605877691849	378.2776276773057
requests	22508	22607	22697
status_codes.200	12278	12332	12381
status_codes.201	2046	2055	2063
status_codes.204	6138	6165	6189
status_codes.400	2046	2055	2064
success	0.9090989870268341	0.909098951652143	0.9090628717451641
throughput	340.9378101334356	342.5067341518986	343.8731369217017
wait	1022005	1037335	874105