Update git-try to find trychange after move.

Update git-try to find trychange after move.

TBR=maruel
BUG=none
TEST=none

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=24064

[chase, 2009-08-22 02:21:34]

After the git-try move, the path to trychange should be updated since it's
calculated based on the location of git-try.

I can't test this before submitting (my git checkout suffered brain damage due
to a system package change), but since git-try is broken before this change and
this should fix it, I want to get this in now instead of waiting.

I will verify git-try is working again once my replacement git checkout is up
and running.

[chase, 2009-08-22 02:58:50]

Follow-up: testing git-try after this change (modified to just to load
TryChange) worked for me.  With the move to depot_tools, git-try should be 100%
again.  Please let me know if you see otherwise.  Thanks.

[M-A Ruel, 2009-08-24 15:38:17]

http://codereview.chromium.org/173249/diff/1/2
File git-try (right):

http://codereview.chromium.org/173249/diff/1/2#newcode105
Line 105: sys.path.append(script_path)
All this stuff is not necessary anymore since both files are in the same
directory.