amrparse: Fix AMR audio exit directly with eos after fast seek.

Skip one byte when not find valid frame in gst_amr_parse_handle_frame().
Otherwise, scan frame size will be bigger after each scan and finally
return GST_FLOW_EOS, which causes audio exit after fast seek.
25 jobs for amrparse in 31 minutes and 38 seconds (queued for 19 seconds)
latest
Status Job ID Name Coverage
  Preparation
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gst indent

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manifest

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  Build
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build cerbero cross-android universal

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build cerbero cross-ios 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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gst-macos-10.14
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build fedora x86_64

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docker windows 1607
build msys2

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build nodebug fedora x86_64

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build static fedora x86_64

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build static nodebug fedora x86_64

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docker windows 1607
build vs2017 amd64

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docker windows 1607
build vs2017 x86

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gst-macos-10.14
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  Test
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check fedora

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integration testsuites fedora

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valgrind bad

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  Integrate
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cross-android universal examples

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gst-ios-12.2 allowed to fail manual
cross-ios universal examples
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documentation

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