ios: Remove the contribs directory before installing new files

If the contribs directory already existed, the source directory was
copied as a new subdirectory into that instead of replacing it
(which probably was what was intended).

This meant that the contribs directory in the install directory
wasn't ever updated in incremental builds unless explicitly
manually removed.
Signed-off-by: Martin Storsjö <martin@martin.st>

extras/package/ios/build.sh

@@ -326,6 +326,7 @@ info "Installing libvlc"
 make install > ${out}
 
 find ${PREFIX}/lib/vlc/plugins -name *.a -type f -exec cp '{}' ${PREFIX}/lib/vlc/plugins \;
+rm -rf "${PREFIX}/contribs"
 cp -R "${VLCROOT}/contrib/${TARGET}-${ARCH}" "${PREFIX}/contribs"
 
 info "Removing unneeded modules"