下面这些依赖库是不是可选的啊？

# Edit the path below to point to the base of your Zlib sources.
ifndef ZLIB_PATH
ZLIB_PATH = ../../zlib-1.2.8
endif
# Edit the path below to point to the base of your OpenSSL package.
ifndef OPENSSL_PATH
OPENSSL_PATH = ../../openssl-1.0.2a
endif
# Edit the path below to point to the base of your LibSSH2 package.
ifndef LIBSSH2_PATH
LIBSSH2_PATH = ../../libssh2-1.5.0
endif
# Edit the path below to point to the base of your librtmp package.
ifndef LIBRTMP_PATH
LIBRTMP_PATH = ../../librtmp-2.4
endif
# Edit the path below to point to the base of your libidn package.
ifndef LIBIDN_PATH
LIBIDN_PATH = ../../libidn-1.32
endif
# Edit the path below to point to the base of your MS IDN package.
# Microsoft Internationalized Domain Names (IDN) Mitigation APIs 1.1
# https://www.microsoft.com/en-us/download/details.aspx?id=734
ifndef WINIDN_PATH
WINIDN_PATH = ../../Microsoft IDN Mitigation APIs
endif
# Edit the path below to point to the base of your Novell LDAP NDK.
ifndef LDAP_SDK
LDAP_SDK = c:/novell/ndk/cldapsdk/win32
endif
# Edit the path below to point to the base of your nghttp2 package.
ifndef NGHTTP2_PATH
NGHTTP2_PATH = ../../nghttp2-1.0.0
endif
--
FROM 124.78.137.*