[processing] fix progress reporting (fix #15521)

(cherry picked from commit b14dfa65fe8c5db852bac0899f8aac64b91faada)

python/plugins/processing/algs/qgis/ConcaveHull.py

@@ -66,7 +66,7 @@ def processAlgorithm(self, progress):
 
         # Delaunay triangulation from input point layer
         progress.setText(self.tr('Creating Delaunay triangles...'))
-        delone_triangles = processing.runalg("qgis:delaunaytriangulation", layer, None, progress=None)['OUTPUT']
+        delone_triangles = processing.runalg("qgis:delaunaytriangulation", layer, None)['OUTPUT']
         delaunay_layer = processing.getObject(delone_triangles)
 
         # Get max edge length from Delaunay triangles
@@ -103,7 +103,7 @@ def processAlgorithm(self, progress):
         # Dissolve all Delaunay triangles
         progress.setText(self.tr('Dissolving Delaunay triangles...'))
         dissolved = processing.runalg("qgis:dissolve", delaunay_layer,
-                                      True, None, None, progress=None)['OUTPUT']
+                                      True, None, None)['OUTPUT']
         dissolved_layer = processing.getObject(dissolved)
 
         # Save result

python/plugins/processing/gui/AlgorithmDialogBase.py

@@ -171,9 +171,6 @@ def setText(self, text):
         self.setInfo(text, False)
         QCoreApplication.processEvents()
 
-    def error(self, text):
-        self.setInfo(text, error=True)
-
     def setParamValues(self):
         pass