Hidden buttons migration fix (#61)

Author: DaymasS

migrations/versions/52230bfc3f86_56_add_is_hidden_field.py

@@ -18,9 +18,10 @@
 
 
 def upgrade():
-    # ### commands auto generated by Alembic - please adjust! ###
-    op.add_column('button', sa.Column('is_hidden', sa.Boolean(), nullable=False))
-    # ### end Alembic commands ###
+    op.add_column('button', sa.Column('is_hidden', sa.Boolean(), nullable=True))
+    conn = op.get_bind()
+    conn.execute(sa.text(f"""UPDATE "button" SET "is_hidden"='false'"""))
+    op.alter_column('button', 'is_hidden', nullable=False)
 
 
 def downgrade():