fixed the OPERA workaround on the 2.1.x branch
fixed the OPERA workaround on the 2.1.x branch

the `includes` function is only on 2.2.x and higher

rlugojr/melonJS,TukekeSoft/melonJS,rlugojr/melonJS,melonjs/melonJS,TukekeSoft/melonJS,srbala/melonJS,gopalindians/melonJS,gopalindians/melonJS,gopalindians/melonJS,melonjs/melonJS,TukekeSoft/melonJS,srbala/melonJS,rlugojr/melonJS,srbala/melonJS