Remove GOMA_HERMETIC form goma.mk

This CL removes the GOMA_HERMETIC setting from goma.mk so that
the default setting will be used. By default, GOMA will fallback
to local compiler if the exactly matched compiler is not available.

Change-Id: I22c83594f6bd30bc8ed1334ab7bb256ef218567b
diff --git a/core/goma.mk b/core/goma.mk
index 0d5f428..c0c27c5 100644
--- a/core/goma.mk
+++ b/core/goma.mk
@@ -46,7 +46,7 @@
   # gomacc can start goma client's daemon process automatically, but
   # it is safer and faster to start up it beforehand. We run this as a
   # background process so this won't slow down the build.
-  $(shell ( GOMA_HERMETIC=error $(goma_ctl) ensure_start ) &> /dev/null &)
+  $(shell ( $(goma_ctl) ensure_start ) &> /dev/null &)
 
   goma_ctl :=
   goma_dir :=