shill: Service: Don't explicitly disconnect on Unload

Set explicitly_disconnected to false during Service::Unload(), so that
autoconnect is possible afterwards if again enabled.

BUG=chromium:149110
TEST=Unit Test

Change-Id: I7d65d3c773aecd03fa70a8469c5e9a31c5ef6b1b
Reviewed-on: https://gerrit.chromium.org/gerrit/33326
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Ready: Philipp Neubeck <pneubeck@chromium.org>
Tested-by: Philipp Neubeck <pneubeck@chromium.org>
diff --git a/service_unittest.cc b/service_unittest.cc
index 5770da7..7e0f8aa 100644
--- a/service_unittest.cc
+++ b/service_unittest.cc
@@ -294,6 +294,7 @@
   service_->Unload();
   EXPECT_EQ(string(""), service_->ui_data_);
   EXPECT_EQ(string(""), service_->guid_);
+  EXPECT_FALSE(service_->explicitly_disconnected_);
 }
 
 TEST_F(ServiceTest, State) {