Switch back to normal slave for s1 again

s1-analytics-slave.eqiad.wmnet caught up replicating, so we can switch
again back to it.

(Compare d4b914defe4156cec301c1382072052d3d41dae7)

Change-Id: I064c621d29ac8aa3400d11a5f1ee92fae4c13d3f