Improved PreferencesMap toString output

Author: cmaglie

Diff for: arduino-core/src/processing/app/helpers/PreferencesMap.java

@@ -248,7 +248,8 @@ public String toString(String indent) {
     String res = indent + "{\n";
     SortedSet<String> treeSet = new TreeSet<>(keySet());
     for (String k : treeSet)
-      res += indent + k + " = " + get(k) + "\n";
+      res += indent + "  " + k + " = " + get(k) + "\n";
+    res += indent + "}\n";
     return res;
   }