Adjust to latest Msys2 kernel release number

Previously 'uname -r' on Msys2 reported a kernele release starting with
2. The latest version starts with 3. In commit 1638623f we specifically
looked for one starting with 2. This is now changed to look for any
digit between 2 and 9.

backpatch to release 10.

src/bin/pg_dump/t/010_dump_connstr.pl

@@ -5,7 +5,7 @@ use PostgresNode;
 use TestLib;
 use Test::More;
 
-if ($^O eq 'msys' && `uname -or` =~ /^2.*Msys/)
+if ($^O eq 'msys' && `uname -or` =~ /^[2-9].*Msys/)
 {
 	plan skip_all => 'High bit name tests fail on Msys2';
 }