doc: Link to LTTng-Analyses releases, not the git tree

doc: Link to LTTng-Analyses releases, not the git tree

Since 0.5+ are not yet supported, the user guide should guide
the user towards downloading the 0.4.x releases.

Change-Id: I8b63a58c8f2d3ed336aba9ee7cdb6fae3a219ac4
Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Reviewed-on: https://git.eclipse.org/r/75767
Reviewed-by: Jonathan Rajotte Julien <jonathan.rajotte-julien@efficios.com>
Reviewed-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Tested-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>