mklog: do not depend on recent unidiff version

contrib/ChangeLog:

	* mklog.py: Check for number of hunks and not if a modified
	file is binary.

contrib/mklog.py

@@ -186,8 +186,9 @@ def generate_changelog(data, no_functions=False, fill_pr_titles=False,
             # contains commented code which a note that it
             # has not been tested due to a certain PR or DR.
             this_file_prs = []
-            if not file.is_binary_file:
-                for line in list(file)[0][0:10]:
+            hunks = list(file)
+            if hunks:
+                for line in hunks[0][0:10]:
                     m = pr_regex.search(line.value)
                     if m:
                         pr = m.group('pr')