Revert "Let 'append_hash' be set by an environment variable."

Doesn't work if it's set in `config-file`.

This reverts commit 5f38074.

Author: Matt Pearson

deploy.sh

@@ -8,7 +8,7 @@ main() {
 	fi
 
 	#append commit hash to the end of message by default
-	append_hash=${GIT_DEPLOY_APPEND_HASH:-true}
+	append_hash=true
 
 	# Parse arg flags
 	while : ; do

readme.md

@@ -17,7 +17,6 @@ You can also define any of variables using environment variables and configurati
 - `GIT_DEPLOY_DIR`
 - `GIT_DEPLOY_BRANCH`
 - `GIT_DEPLOY_REPO`
-- `GIT_DEPLOY_APPEND_HASH`
 
 The script will set these variables in this order of preference: