[Work-around] Update recipe for ImageMagick to avoid bitbake error

[Work-around] Update recipe for ImageMagick to avoid bitbake error

At www.imagemagick.org/download, tarball archives of old patchsets are deleted
when a new patchset is created. This causes error when do_fetch().

Offical source repository is in github, so SRC_URI can be set to pull from there.
Unfortunately, github repository has tags only after 6.9.5-4.
Therefore, updated to the latest stable, 6.9.10-10.

For meta-agl/meta-agl-demo, ImageMagick is not mandatory component,
but optee inside Renesas BSP requires it (and python-wand).

Upstream optee already remove these dependency, so this is
just work-around until meta-renesas-rcar-gen3 will be updated.

Change-Id: I1767e2d7588a35d75009843312c484d3d63553ae
Signed-off-by: Tadao Tanikawa <tanikawa.tadao@jp.panasonic.com>