[refactoring-ode][Mission] Fixed a bug which caused infinite recursion

classes/Mission.m

@@ -11,14 +11,14 @@ classdef Mission < Config
     %               an empty mission
 
     properties
-        name % Mission name, used to access <mission> folder
+        name        char % Mission name, used to access <mission> folder
     end
 
     properties(SetAccess = protected)
-        currentPath
-        configPath
-        dataPath
-        msaPath
+        currentPath char
+        configPath  char
+        dataPath    char
+        msaPath     char
     end
 
     properties(Access = protected)
@@ -32,7 +32,9 @@ classdef Mission < Config
                 m {mustBeA(m, {'logical', 'string', 'char'})} = false
             end
 
-            if ~isa(m, 'string') && isempty(m), return; end
+            if nargin == 0
+                return;
+            end
 
             filePath = fullfile(fileparts(mfilename("fullpath")), '..', 'missions');
             filePath = trimPath(filePath);