Avoid adding false UMat/GpuMat declaration

modules/python/src2/hdr_parser.py

@@ -954,6 +954,7 @@ class CppHeaderParser(object):
                                 has_mat = len(list(filter(lambda x: x[0] in {"Mat", "vector_Mat"}, args))) > 0
                                 if has_mat:
                                     _, _, _, gpumat_decl = self.parse_stmt(stmt, token, mat="cuda::GpuMat", docstring=docstring)
+                                    if gpumat_decl != decl:
                                         decls.append(gpumat_decl)
 
                             if self._generate_umat_decls:
@@ -963,6 +964,7 @@ class CppHeaderParser(object):
                                 has_mat = len(list(filter(lambda x: x[0] in {"Mat", "vector_Mat"}, args))) > 0
                                 if has_mat:
                                     _, _, _, umat_decl = self.parse_stmt(stmt, token, mat="UMat", docstring=docstring)
+                                    if umat_decl != decl:
                                         decls.append(umat_decl)
 
                         docstring = ""