Remove openTypeOS2Type

[probonopd]

https://fontbakery.graphicore.de/report/cd6d27f1-7b34-4e43-96e0-1c9fd74593c1 complains:

FAIL
In this font fsType is set to 4 meaning that:
The font may be embedded, and temporarily loaded on the remote system, but documents that use it must not be editable.

No such DRM restrictions can be enabled on the Google Fonts collection, so the fsType field must be set to zero (Installable Embedding) instead.

http://unifiedfontobject.org/versions/ufo2/fontinfo.plist/ says:

openTypeOS2Type
A list of bit numbers indicating the embedding type. The bit numbers are listed in the OpenType OS/2 specification. Corresponds to the OpenType OS/2 table fsType field.

So far we have

    <key>openTypeOS2Type</key>
    <array>
      <integer>2</integer>
    </array>

Should it be

    <key>openTypeOS2Type</key>
    <array>
     </array>

? cc @davelab6