erp5testnode: install seleniumrunner from a tag

Installing from master is problematic because when master does not build
we don't have test results and we don't see that it's broken.

/reviewed-on nexedi/slapos!474

software/erp5testnode/buildout.hash.cfg

@@ -18,4 +18,4 @@ md5sum = 307663d73ef3ef94b02567ecd322252e
 
 [template-default]
 filename = instance-default.cfg
-md5sum = ff368286a75243d0536ee6a974107b6f
+md5sum = c85bd43145c7d21321546f988aebbfc7

software/erp5testnode/instance-default.cfg

@@ -233,4 +233,4 @@ port = $${shellinabox-frontend:port}
 node-quantity = 1
 test-suite-master-url =
 instance-dict =
-software-path-list = ["https://lab.nexedi.com/nexedi/slapos/raw/master/software/seleniumrunner/software.cfg"]
+software-path-list = ["https://lab.nexedi.com/nexedi/slapos/raw/1.0.83/software/seleniumrunner/software.cfg"]