Revert "Update slapos.core version"

This reverts commit 8251f3dd.

1.4.23 is not available on pypi yet, causing all involved software releases
to fail instanciating, breaking all tests.
Feel free to reapply once the version is actually released.

stack/slapos.cfg

@@ -135,7 +135,7 @@ pytz = 2016.10
 requests = 2.13.0
 six = 1.11.0
 slapos.cookbook = 1.0.92
-slapos.core = 1.4.23
+slapos.core = 1.4.22
 slapos.extension.strip = 0.4
 slapos.extension.shared = 1.0
 slapos.libnetworkcache = 0.16
@@ -150,7 +150,7 @@ xml-marshaller = 0.9.7
 paramiko = 2.1.3
 
 # Required by:
-# slapos.core==1.4.23
+# slapos.core==1.4.22
 Flask = 0.12
 
 # Required by:
@@ -222,7 +222,7 @@ jsonschema = 3.0.0a3
 lockfile = 0.12.2
 
 # Required by:
-# slapos.core==1.4.23
+# slapos.core==1.4.22
 # XXX 'slapos node format' raises an exception with netifaces 0.10.5.
 netifaces = 0.10.4
 
@@ -255,7 +255,7 @@ python-dateutil = 2.7.3
 rpdb = 0.1.5
 
 # Required by:
-# slapos.core==1.4.23
+# slapos.core==1.4.22
 supervisor = 3.3.3
 
 # Required by:
@@ -263,11 +263,11 @@ supervisor = 3.3.3
 tzlocal = 1.5.1
 
 # Required by:
-# slapos.core==1.4.23
+# slapos.core==1.4.22
 uritemplate = 3.0.0
 
 # Required by:
-# slapos.core==1.4.23
+# slapos.core==1.4.22
 zope.interface = 4.3.3
 
 [networkcache]