Form multipart upload: Cannot upload data with custom boundary

Jersey does not reads a multiupload correctly: The client builds the boundary itself this way:
boundary = "===" + System.currentTimeMillis();
And pushes the data with a HTTPURLConnection.
A header for such a multiupload looks like:
Content-Type: multipart/form-data; boundary====1444057544756===

When I add brakers arount it works:
Content-Type: multipart/form-data; boundary="===1444057544756==="

But from RFC also "=" are allowed:
[http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html#z0](http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html#z0)

with PHP (with apache) and other servers it works fine but not with jersey. It reposts me that the Header could not be read.

Hint: I had a look in the sourcecode. Maybe the reader for the header is not correct because it searches for the next "=". But maybe I am wrong, you are the experts 
#### Environment
using following dependencies (in versions above):

org.eclipse.jetty
jetty-server
9.3.4.RC0

org.eclipse.jetty
jetty-servlet
9.3.4.RC0

org.glassfish.jersey.core
jersey-server

org.glassfish.jersey.containers
jersey-container-servlet-core

org.glassfish.jersey.media
jersey-media-multipart

org.glassfish.jersey.media
jersey-media-moxy

#### Affected Versions
[2.7, 2.22]