fix syntax for inline next value

Author: gijzelaerr

sqlalchemy_monetdb/compiler.py

@@ -75,7 +75,7 @@ def visit_mod(self, binary, **kw):
         return self.process(binary.left) + " %% " + self.process(binary.right)
 
     def visit_sequence(self, seq):
-        exc = "(SELECT NEXT VALUE FOR %s)" \
+        exc = "(NEXT VALUE FOR %s)" \
               % self.dialect.identifier_preparer.format_sequence(seq)
         return exc