struct freed before rasied

the ctx struct's freed before the exception ( exc ) is raised - so it references invalid memory

ext/couchbase_ext/couchbase_ext.c- exc = ctx->exception; <----
ext/couchbase_ext/couchbase_ext.c- extended = ctx->extended;
ext/couchbase_ext/couchbase_ext.c: free(ctx); <------
ext/couchbase_ext/couchbase_ext.c- if (exc != Qnil) {
ext/couchbase_ext/couchbase_ext.c- rb_exc_raise(exc); <------
ext/couchbase_ext/couchbase_ext.c- }