tests: fix glob pattern for dynamic timer alignment

The number of space characters varies depending on the number of digits of the
timer, making some tests fail on slow machines in an unintended way:

```diff
--- /build/mercurial-6.1/tests/test-merge-halt.t
+++ /build/mercurial-6.1/tests/test-merge-halt.t.err
@@ -210,6 +210,6 @@
   merge halted after failed merge (see hg resolve)
   [240]
   $ hg shelve --list
-  default         (* ago)    changes to: foo (glob)
+  default         (11s ago)   changes to: foo
   $ hg unshelve --abort
   unshelve of 'default' aborted
ERROR: test-merge-halt.t output changed
```

Differential Revision: https://phab.mercurial-scm.org/D12381

tests/test-merge-halt.t

@@ -210,6 +210,6 b" Check that unshelve isn't broken by halt"
   merge halted after failed merge (see hg resolve)
   [240]
   $ hg shelve --list
-  default         (* ago)    changes to: foo (glob)
+  default         (*s ago) * changes to: foo (glob)
   $ hg unshelve --abort
   unshelve of 'default' aborted

tests/test-shelve.t

@@ -976,7 +976,7 b' Test shelve --keep'
 Test shelve --delete
 
   $ hg shelve --list
-  default         (*s ago)    changes to: create conflict (glob)
+  default         (*s ago) * changes to: create conflict (glob)
   $ hg shelve --delete doesnotexist
   abort: shelved change 'doesnotexist' not found
   [10]
@@ -1209,7 +1209,7 b' Abort unshelve while merging (issue5123)'
   $ hg add e
   $ hg ci -m e
   $ hg shelve --patch
-  default         (*s ago)    changes to: b (glob)
+  default         (*s ago) * changes to: b (glob)
   
   diff --git a/c b/c
   new file mode 100644
@@ -1258,7 +1258,7 b' Abort unshelve while merging (issue5123)'
   e
 -- shelve should not contain `c` now
   $ hg shelve --patch
-  default         (*s ago)    changes to: b (glob)
+  default         (*s ago) * changes to: b (glob)
   
   diff --git a/d b/d
   new file mode 100644
@@ -1357,7 +1357,7 b' Abort unshelve while merging (issue5123)'
   A
   B
   $ hg shelve --patch
-  default         (*s ago)    changes to: add B to foo (glob)
+  default         (*s ago) * changes to: add B to foo (glob)
   
   diff --git a/foo b/foo
   --- a/foo