RFR 8152108: Correct jarsigner warning message about missing timestamp

[Wang Weijun]

Please review this string change for

   https://bugs.openjdk.java.net/browse/JDK-8152108
   Correct jarsigner warning message about missing timestamp

--- a/src/jdk.jartool/share/classes/sun/security/tools/jarsigner/Resources.java
+++ b/src/jdk.jartool/share/classes/sun/security/tools/jarsigner/Resources.java
@@ -247,9 +247,9 @@
         {"This.jar.contains.entries.whose.certificate.chain.is.not.validated.reason.1",
                  "This jar contains entries whose certificate chain is not validated. Reason: %s"},
         {"no.timestamp.signing",
-                "No -tsa or -tsacert is provided and this jar is not timestamped. Without a timestamp, users may not be able to validate this jar after the signer certificate's expiration date (%1$tY-%1$tm-%1$td) or after any future revocation date."},
+                "No -tsa or -tsacert is provided and this jar is not timestamped. Without a timestamp, users may not be able to validate this jar after the signer certificate's expiration date (%1$tY-%1$tm-%1$td)."},
         {"no.timestamp.verifying",
-                "This jar contains signatures that does not include a timestamp. Without a timestamp, users may not be able to validate this jar after the signer certificate's expiration date (%1$tY-%1$tm-%1$td) or after any future revocation date."},
+                "This jar contains signatures that does not include a timestamp. Without a timestamp, users may not be able to validate this jar after the signer certificate's expiration date (%1$tY-%1$tm-%1$td)."},
         {"Unknown.password.type.", "Unknown password type: "},
         {"Cannot.find.environment.variable.",
                 "Cannot find environment variable: "},

The two resource strings are used in signing and verifying, respectively.

Thanks
Max