ENH: add json schema validation for config files

https://gitlab.com/caosdb/caosdb-pylib/-/merge_requests/47

src/caosdb/apiutils.py

@@ -517,9 +517,9 @@ def getOriginUrlIn(folder):
     with open(t.name, "r") as t:
         urlString = "Fetch URL:"
 
-        for l in t.readlines():
-            if urlString in l:
-                return l[l.find(urlString) + len(urlString):].strip()
+        for line in t.readlines():
+            if urlString in line:
+                return line[line.find(urlString) + len(urlString):].strip()
 
     return None