pdfplumber.parser all_row_ids is out of the range in the case of empty page (no words on the page)

[egork520]

Hello @kyleclo I identified an issue in referencing all_word_ids[-1] in case of no words detected on the page. I could try to fix it by checking first if the list is empty. But if you know a better fix please let me know

Here is the page screen shot:

And the paper:

f87f9a26543e03c985867d0dbff1b900ecb6e46d.pdf

Here is the stack trace:

`File ~/Documents/codes/git/ai2/s2/mmda/src/mmda/parsers/pdfplumber_parser.py:170, in PDFPlumberParser.parse(self, input_pdf_path)
166 all_tokens.extend(fine_tokens)
167 all_row_ids.extend(
168 [i + last_row_id + 1 for i in line_ids_of_fine_tokens]
169 )
--> 170 last_row_id = all_row_ids[-1]
171 all_word_ids.extend(
172 [i + last_word_id + 1 for i in word_ids_of_fine_tokens]
173 )
174 last_word_id = all_word_ids[-1]

IndexError: list index out of range
`

[egork520]

Link to the fix: PR