BUG: None-check in DictionaryObject.read_from_stream (#1113)

Guard pdf.strict with check if pdf is None in DictionaryObject.read_from_stream

Closes #1107

PyPDF2/generic.py

@@ -805,7 +805,7 @@ def read_unsized_from_steam(stream: StreamType, pdf: Any) -> bytes:  # PdfReader
                     f"Multiple definitions in dictionary at byte "
                     f"{hex_str(stream.tell())} for key {key}"
                 )
-                if pdf.strict:
+                if pdf is not None and pdf.strict:
                     raise PdfReadError(msg)
                 else:
                     warnings.warn(msg, PdfReadWarning)