Fixed bug in phase which lead to use of data from old calls

proxtoolbox/Problems/Phase/phase.py

@@ -27,7 +27,7 @@ class Phase(Problem):
         ----------
         new_config : dict, optional - Parameters to initialize the problem. If unspecified, the default config is used.
         """
-        self.config.update(new_config)     
+        self.config = new_config     
 
         #call data processor, read data