grid: Fix debian detection

In some cases the debian distribution version string can be returned uppercase.

slapos/grid/distribution.py

@@ -55,6 +55,7 @@ def _debianize(os):
     minor releases would be seen as not compatible to each other.
     """
     distname, version, id_ = os
+    distname = distname.lower()
     if distname == 'debian' and '.' in version:
         version = version.split('.')[0]
     return distname, version, id_

[Ivan Tyagov]

@luke , this breaks tests. See

https://stack.nexedi.com/test_result_module/20200203-41BC7FFE/6?selection_name=test_result_selection&selection_index=1&reset:int=1&selection_key=d055e974ef978d576dfe096a93575da9

For both Py2 / Py3

[Łukasz Nowak]

Reverted, that supposed to land on a branch, sorry.