Fix cb-docker-tool --from-latestbuilds for SGW

Change-Id: I4aef33e6b9830de9360c00ea2314d1d79d9e1741
Reviewed-on: https://review.couchbase.org/c/build-tools/+/193896
Tested-by: Chris Hillery <[email protected]>
Reviewed-by: Blair Watt <[email protected]>

Author: ceejatec

dockerhub/cb-docker-tool

@@ -216,11 +216,16 @@ class DockerTool:
             return
         version, bldnum = self.version.split('-')
         if self.product == "sync-gateway":
+            sgw_filename = (
+                f"couchbase-{self.product}-{self.edition}_{version}"
+                f"-{bldnum}_@@ARCH@@.deb"
+            )
             self.add_templateoverrides([
-                "SGW_PACKAGE=http://latestbuilds.service.couchbase.com/builds/"
+                "SYNC_GATEWAY_PACKAGE_URL="
+                "http://latestbuilds.service.couchbase.com/builds/"
                 f"latestbuilds/{self.product.replace('-','_')}/{version}/"
-                f"{bldnum}/couchbase-{self.product}-{self.edition}_{version}"
-                f"-{bldnum}_@@ARCH@@.deb"
+                f"{bldnum}/{sgw_filename}",
+                f"SYNC_GATEWAY_PACKAGE_FILENAME={sgw_filename}"
             ])
         else:
             self.add_templateoverrides([