calibrate_mh_scale_parameter.m: fix typo in error message

[skip CI]

(cherry picked from commit d5d3e906)

matlab/calibrate_mh_scale_parameter.m

@@ -66,7 +66,7 @@ Parameters = Parameters';
 try
     dd = chol(CovarianceMatrix);
 catch
-    error('The covariance matrix has to be a symetric positive definite matrix!')
+    error('The covariance matrix has to be a symmetric positive definite matrix!')
 end
 
 % Set parameters related to the proposal distribution