bug fix

- fixes bug introduced in v5.1.1 when printing output when bootfun is `mean`

Author: acp29

DESCRIPTION

@@ -1,6 +1,6 @@
 name: statistics-bootstrap
-version: 5.1.1
-date: 2023-01-07
+version: 5.1.2
+date: 2023-01-08
 author: Andrew Penn <andy.c.penn@gmail.com>
 maintainer: Andrew Penn <andy.c.penn@gmail.com>
 title: A statistics package with a variety of bootstrap resampling tools

inst/bootknife.m

@@ -255,6 +255,7 @@
     end
     if ((nargin < 3) || isempty (bootfun))
       bootfun = @mean;
+      bootfun_str = 'mean';
     else
       if (iscell (bootfun))
         if (ischar (bootfun{1}))