Fix pattern parser single-digit clue rows

submodules/rlp/rlp/ascii_parser.py

@@ -37,7 +37,10 @@ def filter_control_chars(text):
         if stripped == "":
             cleaned_lines.append(line)
         elif len(stripped) == 1:
-            continue
+            if stripped.isdigit():
+                cleaned_lines.append(line)
+            else:
+                continue
         elif any(c in line for c in ["|", "#", ".", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]):
             cleaned_lines.append(line)
         elif "+" in line: