When using the WebDAV servlet, the log shows java.io.UnsupportedEncodingException: UTF_8 exceptions on requests.

Reproduction steps;
- Download and unzip tomcat version 7.0.81
- Unzip the webdav.zip webdav in the root of the tomcat.
- Start the Tomcat server 
- Connect with anyclient to http://localhost:8080/webdav/
- See the stacktrace in the console.

java.io.UnsupportedEncodingException: UTF_8
        at sun.nio.cs.StreamEncoder.forOutputStreamWriter(StreamEncoder.java:61)
        at java.io.OutputStreamWriter.<init>(OutputStreamWriter.java:100)
        at org.apache.catalina.util.URLEncoder.encode(URLEncoder.java:170)
        at org.apache.catalina.servlets.WebdavServlet.rewriteUrl(WebdavServlet.java:444)
        at org.apache.catalina.servlets.WebdavServlet.parseProperties(WebdavServlet.java:2122)
        at org.apache.catalina.servlets.WebdavServlet.doPropfind(WebdavServlet.java:702)
<SNIP>

I have traced this to org.apache.catalina.servlets.WebdavServlet.rewriteUrl(String) . The implementation for tc7.x is;
  return URL_ENCODER_XML.encode(path, "UTF_8");
For tc8.5 it is;
  return URL_ENCODER_XML.encode(path, StandardCharsets.UTF_8);

I suspect that this is a pretty simple copy-paste error. The string should probably be changed from "UTF_8" (with underscore) to "UTF-8" (with a dash). But i have not tested this.