Apply suggestions from code review

Author: mseri

packages/aws-s3/aws-s3.4.8.1/opam

@@ -19,7 +19,6 @@ depends: [
   "ptime"
   "uri"
   "ezxmlm" {>= "1.1.0"}
-  "base" {>= "v0.16.0"}
   "ppx_protocol_conv_xmlm" {>= "5.0.0"}
   "ppx_protocol_conv_json" {>= "5.0.0"}
   "yojson"