configure will add a dependency on librtmp.so.0 if the development
package happens to be installed.

(cherry picked from commit f4844a9a)

curl: sigh... *actually* disable rtmp support

(cherry picked from commit 805f12dd)

curl: disable loads more random stuff we don't need

(cherry picked from commit 0b8b96ed)
Change-Id: I0f4bcd73f9e0e7307ca0556a5f6990631eb9f2c5