[core] attribute: Remove redundant backslashes

Author: gregoire-dl

meshroom/core/attribute.py

@@ -1091,7 +1091,7 @@ def _hasKeyableChilds(self) -> bool:
         """
         Whether all child attributes are keyable.
         """
-        return all((isinstance(attribute, ShapeAttribute) and attribute.shapeKeyable) or \
+        return all((isinstance(attribute, ShapeAttribute) and attribute.shapeKeyable) or
                     attribute.keyable for attribute in self.value)
 
     def _getNbObservations(self) -> int:
@@ -1114,8 +1114,8 @@ def hasObservation(self, key: str) -> bool:
         """
         if not self.shapeKeyable:
             return True
-        return all((isinstance(attribute, ShapeAttribute) and attribute.hasObservation(key)) or \
-                   (not isinstance(attribute, ShapeAttribute) and attribute.keyValues.hasKey(key)) \
+        return all((isinstance(attribute, ShapeAttribute) and attribute.hasObservation(key)) or
+                   (not isinstance(attribute, ShapeAttribute) and attribute.keyValues.hasKey(key))
                    for attribute in self.value)
 
     @raiseIfLink