Fix try/except in from_reference shadowing MissingDependencyException (…

…#1939)

dlt/extract/source.py

@@ -31,6 +31,7 @@
  pipeline_state,
 )
 from dlt.common.utils import graph_find_scc_nodes, flatten_list_or_items, graph_edges_to_nodes
+from dlt.common.exceptions import MissingDependencyException
 
 from dlt.extract.items import TDecompositionStrategy
 from dlt.extract.pipe_iterator import ManagedPipeIterator
@@ -601,6 +602,8 @@ def from_reference(cls, ref: str) -> SourceFactory[Any, DltSource]:
  return factory # type: ignore[no-any-return]
  else:
  raise ValueError(f"{attr_name} in {module_path} is of type {type(factory)}")
+ except MissingDependencyException:
+ raise
  except ModuleNotFoundError:
  # raise regular exception later
  pass