Don't pass underlying context if this is a bracketed link.

mwparserfromhell/parser/tokenizer.c

@@ -870,7 +870,7 @@ static int Tokenizer_parse_bracketed_uri_scheme(Tokenizer* self)
     Py_UNICODE this;
     int slashes, i;
 
-    if (Tokenizer_push(self, self->topstack->context | LC_EXT_LINK_URI))
+    if (Tokenizer_push(self, LC_EXT_LINK_URI))
         return -1;
     if (Tokenizer_READ(self, 0) == *"/" && Tokenizer_READ(self, 1) == *"/") {
         if (Tokenizer_emit_text(self, "//"))

mwparserfromhell/parser/tokenizer.py

@@ -315,7 +315,7 @@ class Tokenizer(object):
 
     def _parse_bracketed_uri_scheme(self):
         """Parse the URI scheme of a bracket-enclosed external link."""
-        self._push(self._context | contexts.EXT_LINK_URI)
+        self._push(contexts.EXT_LINK_URI)
         if self._read() == self._read(1) == "/":
             self._emit_text("//")
             self._head += 2