[BUGFIX] CurlEngine tries to rewind stream

This fixes an issue with the CurlEngine which executes a
rewind() if the given request content is a stream resource.

This is not necessary and is especially harmful if a stream
resource is provided which does not support seek operations.

Change-Id: I4b4629737540cf106a23ac554d58c2b459d2a1c3
Resolves: #50636
Releases: 2.0, master