Updated from global requirements

Change-Id: If72d3129e09ddcc2b1d944a71c7397cc85218af9

requirements.txt

@@ -5,7 +5,7 @@
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 iso8601>=0.1.11 # MIT
 lxml!=3.7.0,>=3.4.1 # BSD
-oslo.config>=4.6.0 # Apache-2.0
+oslo.config>=5.1.0 # Apache-2.0
 docutils>=0.11 # OSI-Approved Open Source, Public Domain
 sphinx>=1.6.2 # BSD
 demjson>=2.2.2 # GLGPLv3+