flowmatching condition shape fix (#1584)

* flowmatching condition shape fix

* self.condition shape not condition shape for fix

Author: gmoss13

sbi/neural_nets/estimators/flowmatching_estimator.py

@@ -119,7 +119,7 @@ def forward(self, input: Tensor, condition: Tensor, t: Tensor) -> Tensor:
         # and remember the original shape
         target_shape = input.shape
         input = input.reshape(-1, input.shape[-1])
-        condition = condition.reshape(-1, condition.shape[-1])
+        condition = condition.reshape(-1, *self.condition_shape)
         t = t.reshape(-1, t.shape[-1])
 
         # embed the input and condition