Fix undefined variable 'val' in tools/editconf.py (#2137)

Merges #2137.

tools/editconf.py

@@ -136,8 +136,9 @@ while len(input_lines) > 0:
 # Put any settings we didn't see at the end of the file,
 # except settings being cleared.
 for i in range(len(settings)):
-	if (i not in found) and not (not val and erase_setting):
+	if i not in found:
 		name, val = settings[i].split("=", 1)
+		if not (not val and erase_setting):
 			buf += name + delimiter + val + "\n"
 
 if not testing: