Check pkgconfig for openssl, since 0.9.7 (a) uses it, and (b) depends on

Check pkgconfig for openssl, since 0.9.7 (a) uses it, and (b) depends on

	* configure.in: Check pkgconfig for openssl, since 0.9.7 (a) uses
	it, and (b) depends on lots of new things sometimes (like on RH9).

	* libsoup/soup-openssl.c:
	* libsoup/soup-ssl-proxy.c: Change #ifdef HAVE_OPENSSL_SSL_H to
	just #ifdef HAVE_OPENSSL since the header check doesn't get run in
	the pkgconfig case