With a non-standard installation of openssl we get this error:
checking run-time libs availability... failed
configure: error: one or more libs available at link-time are not available run-time. Libs used at link-time: -lnghttp2 -lssl -lcrypto -lssl -lcrypto -lz
There's already code to set LD_LIBRARY_PATH on Linux, so set
DYLD_LIBRARY_PATH equivalent on macOS.
Closes#8028