package/htop: remove 0xe2 from MetersPanel.c

This non ascii character trigger an issue with MakeHeader.py.

./scripts/MakeHeader.py MetersPanel.c
Traceback (most recent call last):
  File "./scripts/MakeHeader.py", line 32, in <module>
    for line in file.readlines():
  File "[...]/output/host/lib/python3.6/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 956: ordinal not in range(128)

Fixes:
http://autobuild.buildroot.net/results/8ed/8edb78b054a265447fd0e83f67cba5f978be4ed6



Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>