opengl: enforce use of non-power-of-2-textures when drawing using Open GL ES 2, since those are supported by specification
opengl: enforce use of non-power-of-2-textures when drawing using Open GL ES 2, since those are supported by specification

Hence, checks for extensions adding this feature will fail.

This solves a green line issue on Apple's ES2 platform

shyamalschandra/vlc,krichter722/vlc,vlc-mirror/vlc,jomanmuk/vlc-2.2,vlc-mirror/vlc-2.1,krichter722/vlc,xkfz007/vlc,shyamalschandra/vlc,xkfz007/vlc,krichter722/vlc,vlc-mirror/vlc-2.1,vlc-mirror/vlc,xkfz007/vlc,vlc-mirror/vlc,vlc-mirror/vlc-2.1,vlc-mirror/vlc,jomanmuk/vlc-2.1,jomanmuk/vlc-2.1,jomanmuk/vlc-2.1,jomanmuk/vlc-2.2,shyamalschandra/vlc,jomanmuk/vlc-2.2,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.1,vlc-mirror/vlc-2.1,xkfz007/vlc,xkfz007/vlc,jomanmuk/vlc-2.2,vlc-mirror/vlc-2.1,vlc-mirror/vlc,jomanmuk/vlc-2.1,jomanmuk/vlc-2.1,xkfz007/vlc,vlc-mirror/vlc,xkfz007/vlc,shyamalschandra/vlc,krichter722/vlc,vlc-mirror/vlc,vlc-mirror/vlc-2.1,krichter722/vlc,shyamalschandra/vlc,jomanmuk/vlc-2.2,krichter722/vlc,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,krichter722/vlc,shyamalschandra/vlc,jomanmuk/vlc-2.1,shyamalschandra/vlc