Win32: skip OpenSSL dependency generation to conserve time.

Disabling the build dependency feature is safe assuming that
nginx/Windows release zip is always built from a clean tree.
This allows to speed up total build time by around 40%.

As it may not be suitable in general, the option resides here
and not in configure.

misc/GNUmakefile

@@ -76,7 +76,8 @@ win32:
 		--with-stream_realip_module				\
 		--with-stream_ssl_preread_module			\
 		--with-openssl=$(OBJS)/lib/$(OPENSSL)			\
-		--with-openssl-opt="no-asm no-tests -D_WIN32_WINNT=0x0501" \
+		--with-openssl-opt="no-asm no-tests no-makedepend	\
+			-D_WIN32_WINNT=0x0501"				\
 		--with-http_ssl_module					\
 		--with-mail_ssl_module					\
 		--with-stream_ssl_module