RFR 8184315: Typo in java.net.JarURLConnection.getCertificates() method documentation

[Chris Hegarty]

Trivial typo fixes to: 1) use the simple present tense of the verb, and
2) correctly pluralize the return value. Similar to that of
JarEntry::getCertificates.

--- a/src/java.base/share/classes/java/net/JarURLConnection.java
+++ b/src/java.base/share/classes/java/net/JarURLConnection.java
@@ -279,35 +279,35 @@
       ....

      /**
-     * Return the Certificate object for this connection if the URL
+     * Returns the Certificate objects for this connection if the URL
       * for it points to a JAR file entry, null otherwise. This method
       * can only be called once
       * the connection has been completely verified by reading
       * from the input stream until the end of the stream has been
       * reached. Otherwise, this method will return {@code null}
       *
       * @return the Certificate object for this connection if the URL
       * for it points to a JAR file entry, null otherwise.
       *
       * @exception IOException if getting the JAR entry causes an
       * IOException to be thrown.
       *
       * @see #getJarEntry
       */
      public java.security.cert.Certificate[] getCertificates()
           throws IOException

-Chris.