title: Tomcat not allowing backslash in URLs in 9.0.7
body: <p>I see that in <a href="https://bz.apache.org/bugzilla/show_bug.cgi?id=62273" rel="nofollow noreferrer">this patch</a> Tomcat added an option to 9.0.8 to allow <code>\</code> in the URL. We have some PDFs that launch to a page such as <code>https://mrbusche.com/?FilePath=\manuals\Commerciallines\eManual\az.pdf</code> Tomcat 9.0.7 is currently blocking the URL due to spec RFC 7230 and RFC 3986. </p>
  
  <p>Exception</p>
  
  <pre><code>Type Exception Report
  
  Message Invalid character found in the request target. 
  The valid characters are defined in RFC 7230 and RFC 3986
  
  Description The server cannot or will not process the request due to something
  that is perceived to be a client error (e.g., malformed request syntax
  , invalid request message framing, or deceptive request routing).
  
  Exception
  
  java.lang.IllegalArgumentException: Invalid character found in the request target. 
  The valid characters are defined in RFC 7230 and RFC 3986
  </code></pre>
  
  <p>Is this simply not possible on Tomcat 9.0.7?</p>
  
  <p>Here's my connector for Tomcat </p>
  
  <pre><code>&lt;Connector
      port="4005"
      connectionTimeout="20000"
      maxHttpHeaderSize="8192"
      minSpareThreads="25"
      enableLookups="false"
      disableUploadTimeout="true"
      acceptCount="100"
      scheme="https"
      secure="true"
      URIEncoding="UTF-8"
      protocol="org.apache.coyote.http11.Http11Nio2Protocol"
      maxThreads="150"
      relaxedQueryChars="\"
      SSLEnabled="true" &gt;
  &lt;/Connector&gt;
  </code></pre>