AttributeError: 'MergedCell' object attribute 'hyperlink' is read-only
*Created originally on Bitbucket by [mxhryvo (Max Henke)](https://bitbucket.org/%7B6e6b3259-9162-488a-bab7-2a3c98755b69%7D/)*
using openpyxl=2.6.2
when loading a workbook, at least for some, the following error happens:
wb = load_workbook(filename=path, data_only=True, keep_links=False)
(tried without keep_links too)
error:
```
wb = load_workbook(filename=path, data_only=True, keep_links=False)
File "C:\Users\XXX\AppData\Local\Programs\Python\Python37-32\lib\site-packages\openpyxl\reader\excel.py", line 312, in load_workbook
reader.read()
File "C:\Users\XXX\AppData\Local\Programs\Python\Python37-32\lib\site-packages\openpyxl\reader\excel.py", line 274, in read
self.read_worksheets()
File "C:\Users\XXX\AppData\Local\Programs\Python\Python37-32\lib\site-packages\openpyxl\reader\excel.py", line 228, in read_worksheets
ws_parser.bind_all()
File "C:\Users\XXX\AppData\Local\Programs\Python\Python37-32\lib\site-packages\openpyxl\worksheet\_reader.py", line 405, in bind_all
self.bind_hyperlinks()
File "C:\Users\XXX\AppData\Local\Programs\Python\Python37-32\lib\site-packages\openpyxl\worksheet\_reader.py", line 373, in bind_hyperlinks
self.ws[link.ref].hyperlink = link
AttributeError: 'MergedCell' object attribute 'hyperlink' is read-only
```
issue