artifactory: add st_size to ArtifactoryFileStat (#453) (#454)

Author: doronz88

Diff for: artifactory.py

@@ -610,6 +610,7 @@ def _get_base_url(self, url):
         "modified_by",
         "mime_type",
         "size",
+        "st_size",
         "sha1",
         "sha256",
         "md5",
@@ -909,6 +910,7 @@ def stat(self, pathobj):
             modified_by=jsn.get("modifiedBy"),
             mime_type=jsn.get("mimeType"),
             size=int(jsn.get("size", "0")),
+            st_size=int(jsn.get("size", "0")),
             sha1=checksums.get("sha1", None),
             sha256=checksums.get("sha256", None),
             md5=checksums.get("md5", None),