[FIX] controller_report_xls: Font Height

Before this change there was a traceback when a `font-size` was added:
```python
File "/usr/local/lib/python3.8/dist-packages/xlwt/BIFFRecords.py", line 725, in __init__
    self._rec_data = pack('<5H4B%ds' % uname_len, height, options, colour_index, weight, escapement,
Exception

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/odoo/instance/odoo/odoo/http.py", line 654, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/home/odoo/instance/odoo/odoo/http.py", line 301, in _handle_exception
    raise exception.with_traceback(None) from new_cause
struct.error: required argument is not an integer
```

That happened because the `height` expected for the fonts is an integer
value and the `get_font_height` was returning `float` values, for
example: "125.0", now we are rounding the new size to 0 decimals to
return the closest integer for that size.

controller_report_xls/reports/xfstyle.py

@@ -291,8 +291,8 @@ def get_font_height(height):
         factor = 1.5
     elif height == "XX-LARGE":
         factor = 2
-    new_size = float(size * factor * 20)
-    return new_size
+    # NOTE: Rounding without decimals because the expected `height` needs to be an `integer` value
+    return round(size * factor * 20)
 
 
 def get_horizontal_align(halign, align):