Revert "Improve default entrypoint cmd"

This reverts commit 6f7360b.
Fixes some error messages, shell command should be passed as full argument

Author: mblaschke

docker/base/alpine-3/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/centos-7/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/debian-7/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/debian-8/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/debian-9/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/ubuntu-12.04/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/ubuntu-14.04/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/ubuntu-15.04/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/ubuntu-15.10/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"

docker/base/ubuntu-16.04/conf/bin/entrypoint.d/default.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec su -c "$@"
+exec "$@"