Bump imagemagick to 7.0.8-39.

Bump imagemagick to 7.0.8-39.

diff --git a/image/base/install-imagemagick b/image/base/install-imagemagick
index e104dcf..2685e87 100755
--- a/image/base/install-imagemagick
+++ b/image/base/install-imagemagick
@@ -1,7 +1,7 @@
 #!/bin/bash
 set -o errexit
 
-IMAGE_MAGICK_VERSION="7.0.8-35"
+IMAGE_MAGICK_VERSION="7.0.8-39"
 LIBPNG_VERSION="1.6.36"
 
 PREFIX=/usr/local

GitHub sha: f727e7c8