Simplify code: Using JRE method instead of custom algorithm

Author: mkarg

src/main/java/com/beust/jcommander/DefaultUsageFormatter.java

@@ -404,13 +404,8 @@ public static String getI18nString(ResourceBundle bundle, String key, String def
      *
      * @return count-many spaces
      */
-    public static CharSequence s(int count) {
-        StringBuilder result = new StringBuilder();
-
-        for (int i = 0; i < count; i++) {
-            result.append(" ");
-        }
-        return result;
+    public static String s(int count) {
+        return " ".repeat(count);
     }
 
     /**

src/main/java/com/beust/jcommander/JCommander.java

@@ -1566,13 +1566,8 @@ public String getParsedAlias() {
     /**
      * @return n spaces
      */
-    private CharSequence s(int count) {
-        StringBuilder result = new StringBuilder();
-        for (int i = 0; i < count; i++) {
-            result.append(" ");
-        }
-
-        return result;
+    private String s(int count) {
+        return " ".repeat(count);
     }
 
     /**