change ytviews model target 20 to 50

backend/app/app/models/ytviews.py

@@ -20,7 +20,7 @@ class YTViews(Base):
   area = Column(String(20))
   language = Column(String(20))
   ages = Column(String(30))
-  target = Column(String(20))
+  target = Column(String(50))
   theme = Column(String(20))
   taxID = Column(String(20))
   item = Column(String(20), nullable=False)