Build: Fix javadoc errors with Oracle JDK

Tested with 12.0.2

core/java/src/net/i2p/app/package.html

@@ -7,12 +7,12 @@ the that interface instead of being started with main().
 </p>
 <p>
 The benefits for clients using this interface:
+</p>
 <ul>
 <li>Get the current context via the constructor
 <li>Complete life cycle management by the router
 <li>Avoid the need for static references
 <li>Ability to find other clients without using static references
 </ul>
-</p>
 </body>
 </html>

core/java/src/net/i2p/crypto/elgamal/package.html

@@ -4,7 +4,7 @@
    Copied from Bouncy Castle 1.53.
 </p><p>
    Since 0.9.25.
-</p><p><pre>
+</p><pre>
 
 
 Copyright (c) 2000 - 2013 The Legion of the Bouncy Castle Inc. (http://www.bouncycastle.org)
@@ -25,5 +25,5 @@ DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 
-</pre></p>
+</pre>
 </body></html>