Omit useless argument

core/src/main/java/hudson/Proc.java

@@ -231,7 +231,7 @@ public abstract class Proc {
                 m.clear();
                 for (String e : env) {
                     int idx = e.indexOf('=');
-                    m.put(e.substring(0,idx),e.substring(idx+1,e.length()));
+                    m.put(e.substring(0,idx),e.substring(idx+1));
                 }
             }
             return pb;