testing/msgpuck: disable on x86

One test fails:

    ok 91 - mp_read_double(mp_encode_float(6.565e6)) check result
    ok 92 - mp_read_double(mp_encode_double(-5.555)) check success
    ok 93 - mp_read_double(mp_encode_double(-5.555)) check pos advanced
    not ok 94 - mp_read_double(mp_encode_double(-5.555)) check result
        # Looks like you failed 1 test of 96 run.
    #   Failed test 'subtests'
    #   in /home/buildozer/aports/testing/msgpuck/src/msgpuck-2.0/test/test.c at line 85
    # Looks like you failed 1 test of 20 run.
    ok 95 - mp_read_double(mp_encode_strl(100)) check fail
    ok 96 - mp_read_double(mp_encode_strl(100)) check pos unchanged
    # *** test_numbers: done ***
    not ok 19 - subtests

Reported to upstream: rtsisyk/msgpuck#17

testing/msgpuck/APKBUILD

@@ -5,7 +5,7 @@ pkgver=2.0
 pkgrel=0
 pkgdesc="A simple and efficient MsgPack binary serialization library"
 url="https://github.com/rtsisyk/msgpuck"
-arch="all"
+arch="all !x86"
 license="BSD-2"
 makedepends="cmake doxygen"
 subpackages="$pkgname-dev $pkgname-doc"