[enhancement](Nereids) remove redundant log when fall back to legacy parser (#13243)

fe/fe-core/src/main/java/org/apache/doris/qe/ConnectProcessor.java

@@ -266,8 +266,8 @@ public class ConnectProcessor {
                 } catch (Exception e) {
                     nereidsParseException = e;
                     // TODO: We should catch all exception here until we support all query syntax.
-                    LOG.warn(" Fallback to stale planner."
-                            + " Nereids cannot process this statement: \"{}\".", originStmt, e);
+                    LOG.info(" Fallback to stale planner."
+                            + " Nereids cannot process this statement: \"{}\".", originStmt.toString());
                 }
             }
             // stmts == null when Nereids cannot planner this query or Nereids is disabled.