templates: fix missed space between instability labels

mercurial/templates/map-cmdline.default

@@ -82,5 +82,6 b' labelcset(expr) = label(separate(" ",'
                                  "changeset.{phase}",
                                  if(obsolete, "changeset.obsolete"),
                                  if(instabilities, "changeset.unstable"),
-                                 instabilities % "instability.{instability}"),
+                                 join(instabilities
+                                      % "instability.{instability}", " ")),
                         expr)

tests/test-obsolete.t

@@ -963,7 +963,7 b' test the obsolete labels'
   
 
   $ hg log -T default -r 'phasedivergent()' --color=debug
-  [log.changeset changeset.draft changeset.unstable instability.orphaninstability.phase-divergent|changeset:   7:50c51b361e60]
+  [log.changeset changeset.draft changeset.unstable instability.orphan instability.phase-divergent|changeset:   7:50c51b361e60]
   [log.user|user:        test]
   [log.date|date:        Thu Jan 01 00:00:00 1970 +0000]
   [log.instability|instability: orphan, phase-divergent]