use raise from test_pr1475*.py

tests/bugfixes/github/test_pr1475_AVIF.py

@@ -1,11 +1,12 @@
 # -*- coding: utf-8 -*-
 
 import system_tests
+import unittest
 
-# test needs system_tests.BT.vv.enable_bmff=1
-enable_bmff = 'enable_bmff'
-vv=system_tests.BT.verbose_version()
-bSkip = not (enable_bmff in vv and vv[enable_bmff] == '1')
+# test needs system_tests.BT.vv['enable_bmff']=1
+bSkip=system_tests.BT.verbose_version().get('enable_bmff')!='1'
+if bSkip:
+    raise unittest.SkipTest('*** requires enable_bmff=1 ***')
 
 class pr_1475_avif_avif(metaclass=system_tests.CaseMeta):
     url = "https://github.com/Exiv2/exiv2/pull/1475"

tests/bugfixes/github/test_pr1475_HEIC.py

@@ -1,11 +1,12 @@
 # -*- coding: utf-8 -*-
 
 import system_tests
+import unittest
 
-# test needs system_tests.BT.vv.enable_bmff=1
-vv=system_tests.BT.verbose_version()
-enable_bmff = 'enable_bmff'
-bSkip = not (enable_bmff in vv and vv[enable_bmff] == '1')
+# test needs system_tests.BT.vv['enable_bmff']=1
+bSkip=system_tests.BT.verbose_version().get('enable_bmff')!='1'
+if bSkip:
+    raise unittest.SkipTest('*** requires enable_bmff=1 ***')
 
 class pr_1475_2021_heic(metaclass=system_tests.CaseMeta):
     url = "https://github.com/Exiv2/exiv2/pull/1475"

tests/bugfixes/github/test_pr1475_HIF.py

@@ -1,11 +1,12 @@
 # -*- coding: utf-8 -*-
 
 import system_tests
+import unittest
 
-# test needs system_tests.BT.vv.enable_bmff=1
-vv=system_tests.BT.verbose_version()
-enable_bmff = 'enable_bmff'
-bSkip = not (enable_bmff in vv and vv[enable_bmff] == '1')
+# test needs system_tests.BT.vv['enable_bmff']=1
+bSkip=system_tests.BT.verbose_version().get('enable_bmff')!='1'
+if bSkip:
+    raise unittest.SkipTest('*** requires enable_bmff=1 ***')
 
 class pr_1475_Sony_hif(metaclass=system_tests.CaseMeta):
     url = "https://github.com/Exiv2/exiv2/pull/1475"