Merge pull request #7242 from scientificlinux/sl7

Update sl container for sl7 to current (build-date=20200107)

library/sl

@@ -8,7 +8,7 @@ Tags: 7, latest
 Architectures: amd64
 GitFetch: refs/heads/7
 Directory: sl7
-GitCommit: 565b44ef66f3fe06ac95cd202efccc7993810bd4
+GitCommit: b875059814e34ceae1c53790e63318712e37aaa9
 
 # For the SL6 container
 Tags: 6