dev: ensure dev.env is posix compatible

the '==' operator is not posix; you're supposed to use a single '='

Signed-off-by: Vicent Marti <[email protected]>

dev.env

@@ -1,13 +1,13 @@
 # No shebang line as this script is sourced from an external shell.
 
 # Copyright 2019 The Vitess Authors.
-# 
+#
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
-# 
+#
 #     http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -34,6 +34,6 @@ export PATH
 
 # According to https://github.com/etcd-io/etcd/blob/a621d807f061e1dd635033a8d6bc261461429e27/Documentation/op-guide/supported-platform.md,
 # currently, etcd is unstable on arm64, so ETCD_UNSUPPORTED_ARCH should be set.
-if [ "$(uname -m)" == aarch64 ]; then
+if [ "$(uname -m)" = aarch64 ]; then
     export ETCD_UNSUPPORTED_ARCH=arm64
 fi