http: remove redundant keepAliveTimeoutBuffer assignment #3186

Job	Run time
Build slim tarball	1m 32s
x86_64-darwin: with shared libraries	45m 14s
x86_64-linux: with shared libraries	34m 22s
aarch64-linux: with shared libraries	28m 8s
aarch64-darwin: with shared libraries	2h 23m 6s
	4h 12m 22s

Provide feedback