Bump lower constraint of MarkupSafe

setuptools 46.0.0's drop of the Features feature broke
python-openstackclient's lower-constraints job on master
via the MarkupSafe package. Bump the lower constraint of
MarkupSafe to fix lower-constraints on master.

Change-Id: Ib0a6f94a6611b221efbf76f6f25b55c43782546f

Author: rubasov

lower-constraints.txt

@@ -41,7 +41,7 @@ jsonschema==2.6.0
 keystoneauth1==3.14.0
 kombu==4.0.0
 linecache2==1.0.0
-MarkupSafe==1.0
+MarkupSafe==1.1.0
 mccabe==0.2.1
 mock==2.0.0
 monotonic==0.6