Fix indentation-detection at indent level 0.

This correctly formats:
  {
    a;
  }
where { is incorrectly indented by 2, but is at level 0, when
reformatting only 'a;'.

llvm-svn: 174737
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index df0b296..a8c327a 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -2593,7 +2593,12 @@
                         "           b;\n"
                         "}\n"
                         "}", 22, 2, getLLVMStyle()));
-} 
+  EXPECT_EQ("  {\n"
+            "    a;\n"
+            "  }", format("  {\n"
+                          "a;\n"
+                          "  }", 4, 2, getLLVMStyle()));
+}
 
 } // end namespace tooling
 } // end namespace clang