Update urllib3 from 1.22 to 1.23 (#4114)

requirements/common.txt

@@ -187,9 +187,9 @@ elasticsearch==6.3.1 \
     --hash=sha256:aada5cfdc4a543c47098eb3aca6663848ef5d04b4324935ced441debc11ec98b
 
 # required by requests and elasticsearch
-urllib3==1.22 \
-    --hash=sha256:06330f386d6e4b195fbfc736b297f58c5a892e4440e54d294d7004e3a9bbea1b \
-    --hash=sha256:cc44da8e1145637334317feebd728bd869a35285b93cbb4cca2577da7e62db4f
+urllib3==1.23 \
+    --hash=sha256:b5725a0bd4ba422ab0e66e89e030c806576753ea3ee08554382c14e685d117b5 \
+    --hash=sha256:a68ac5e15e76e7e5dd2b8f94007233e01effe3e50e8daddf69acfd81cb686baf
 
 certifi==2018.8.24 \
     --hash=sha256:456048c7e371c089d0a77a5212fb37a2c2dce1e24146e3b7e0261736aaeaa22a \