'bashise' conf/mysql & apply shellcheck fixes

Author: JedMeister

conf/mysql

@@ -1,9 +1,13 @@
-#!/bin/sh -e
+#!/bin/bash -e
 
 # download mysqltuner
 dl() {
-    [ "$FAB_HTTP_PROXY" ] && PROXY="--proxy $FAB_HTTP_PROXY"
-    cd $2; curl -L -f -O $PROXY $1; cd -
+    if [[ "$FAB_HTTP_PROXY" ]]; then
+       PROXY=(--proxy "$FAB_HTTP_PROXY")
+    fi
+    cd "$2"
+    curl -L -f -O "${PROXY[@]}" "$1"
+    cd -
 }
 
 # Install mysqltuner at "latest" tag (via gh_releases) and from core dev's