Update rls

Changes:
- deps: update racer and cargo

diff --git a/src/tools/rls b/src/tools/rls
index dd341d53075411cf0f71c5853c98facda35112ef..a0e80a9783b1485fe8935d5de4dec34fe6bb5f10 160000 (submodule)
--- a/src/tools/rls
+++ b/src/tools/rls
@@ -1 +1 @@
-Subproject commit dd341d53075411cf0f71c5853c98facda35112ef
+Subproject commit a0e80a9783b1485fe8935d5de4dec34fe6bb5f10