This function is no longer necessary because 0x00 concatenation rule
is gone.

libjemalloc as static library requires -pthread flag to link.  Without
that, the check in configure.ac fails with unresolved symbols.

Thanks to Pascal

NGHTTP2_ERR_TEMPORAL_CALLBACKFAILURE is not supported in
on_frame_recv_callback.

I went through and fixed the English and grammar somwhat