glcontext_egl: fix glcontext fail when egl support EGL_KHR_no_config_context

eglchooseconfig() will return NULL config when no valid config found, eg when
try GLES 3.2 on GLES 2.0 platform, but this will not make create context fail
because it support EGL_KHR_no_config_context, and will fail later.

Need also check numconfig if support EGL_KHR_no_config_context
20 jobs for egl_bug in 61 minutes and 6 seconds (queued for 2 seconds)
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gst indent

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manifest

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  Build
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build fedora x86_64

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build nodebug fedora x86_64

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check fedora

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integration testsuites fedora

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  Full Builds
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build cerbero android universal

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build cerbero cross win32

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build cerbero cross win64

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build cerbero fedora x86_64

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  Full Tests
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valgrind bad

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valgrind base

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valgrind ges

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valgrind good

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valgrind ugly

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valgrind base

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valgrind good

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  Apps
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android universal examples

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  Deploy
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documentation

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