Fix dependency for ui_tests

LineMapperTest depends on //gerrit-common:client but it wasn't
added as a dependency in the BUCK file.

Change-Id: Id108888169427cdffd19095dd253b4a90ec91ba2
diff --git a/gerrit-gwtui/BUCK b/gerrit-gwtui/BUCK
index fbd493f..ef8d3cb 100644
--- a/gerrit-gwtui/BUCK
+++ b/gerrit-gwtui/BUCK
@@ -92,6 +92,7 @@
   ],
   deps = [
     ':ui_module',
+    '//gerrit-common:client',
     '//lib:junit',
     '//lib/gwt:dev',
     '//lib/gwt:user',