slaprunner: adjust shell $PATH to use first slapos provided commands

Only use /usr/bin:/bin/ as a fallback.

software/slaprunner/buildout.hash.cfg

@@ -19,7 +19,7 @@ md5sum = 713db528880282d568278f09458d2aab
 
 [template-runner]
 filename = instance-runner.cfg
-md5sum = 9811c8879a6da37486f7dcf9dc0bf0d2
+md5sum = 0da09ef60256982d9335ab081b11b250
 
 [template-runner-import-script]
 filename = template/runner-import.sh.jinja2

software/slaprunner/instance-runner.cfg

@@ -647,7 +647,7 @@ recipe = slapos.cookbook:shell
 wrapper = $${directory:bin}/bash
 shell = ${bash:location}/bin/bash
 home = $${buildout:directory}
-path = /usr/bin:/bin/:${nano:location}/bin:${vim:location}/bin:${screen:location}/bin:${git:location}/bin:${tig:location}/bin
+path = ${nano:location}/bin:${vim:location}/bin:${screen:location}/bin:${git:location}/bin:${tig:location}/bin:/usr/bin:/bin/:
 ps1 = "\\w> "
 
 [prepare-software]