COPY: remove unsupported storage drivers from warning message

COPY: remove unsupported storage drivers from warning message

diff --git a/launcher b/launcher
index ef73c5f..6a09c0c 100755
--- a/launcher
+++ b/launcher
@@ -155,7 +155,7 @@ check_prereqs() {
   # 2. running an approved storage driver?
   if ! $docker_path info 2> /dev/null | egrep -q '^Storage Driver: (aufs|zfs|overlay2)$'; then
     echo "Your Docker installation is not using a supported storage driver.  If we were to proceed you may have a broken install."
-    echo "aufs is the recommended storage driver, although zfs/btrfs/overlay and overlay2 may work as well."
+    echo "aufs is the recommended storage driver, although zfs and overlay2 may work as well."
     echo "Other storage drivers are known to be problematic."
     echo "You can tell what filesystem you are using by running \"docker info\" and looking at the 'Storage Driver' line."
     echo

GitHub sha: 64716d41

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