Fix the rst doc, unbreak buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@371968 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/clang-tidy/checks/performance-inefficient-vector-operation.rst b/docs/clang-tidy/checks/performance-inefficient-vector-operation.rst
index 2d4b3d1..f327ac2 100644
--- a/docs/clang-tidy/checks/performance-inefficient-vector-operation.rst
+++ b/docs/clang-tidy/checks/performance-inefficient-vector-operation.rst
@@ -60,6 +60,7 @@
    ``::std::vector`` is considered.
 
 .. option:: EnableProto
+
    When non-zero, the check will also warn on inefficient operations for proto
    repeated fields. Otherwise, the check only warns on inefficient vector
    operations. Default is `0`.