Remove the DigestFunction startup flag in bazelrc.tpl. (#184)

Bazel uses SHA256 by default since a couple of releases:
https://github.com/bazelbuild/bazel/commit/d3fed125d00f6f61bfbfe05f4566656cdac1ea6e#diff-7dff227a8d623e0469c26b9316161435
diff --git a/release/bazelrc.tpl b/release/bazelrc.tpl
index 9ffd536..714a21c 100644
--- a/release/bazelrc.tpl
+++ b/release/bazelrc.tpl
@@ -9,9 +9,6 @@
 # This .bazelrc file also contains all of the flags required for the local
 # docker sandboxing.
 
-# Remote Build Execution requires a strong hash function, such as SHA256.
-startup --host_jvm_args=-Dbazel.DigestFunction=SHA256
-
 # Depending on how many machines are in the remote execution instance, setting
 # this higher can make builds faster by allowing more jobs to run in parallel.
 # Setting it too high can result in jobs that timeout, however, while waiting