tests: removed redundant "-u test" from test scripts
The tests are executed with a .hgrc file which adds "-u test" by
default.
hg: config error at .../t/.hg/hgrc:1: 'invalid'
updating working directory
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
[paths]
default = .../foo%%bar
default = .../foo%%bar
bundle.mainreporoot=.../foobar
defaults.backout=-d "0 0"
defaults.commit=-d "0 0"
defaults.debugrawcommit=-d "0 0"
defaults.tag=-d "0 0"
paths.default=.../foo%%bar
ui.slash=True