feat: remove printStackTrace from exception handlers (#84)

Author: hsluoyz

src/main/java/org/casbin/adapter/JDBCBaseAdapter.java

@@ -284,8 +284,6 @@ public void savePolicy(Model model) {
                 conn.commit();
             } catch (SQLException e) {
                 conn.rollback();
-
-                e.printStackTrace();
                 throw e;
             } finally {
                 conn.setAutoCommit(true);
@@ -375,8 +373,6 @@ public void addPolicies(String sec, String ptype, List<List<String>> rules) {
                 conn.commit();
             } catch (SQLException e) {
                 conn.rollback();
-
-                e.printStackTrace();
                 throw e;
             } finally {
                 conn.setAutoCommit(true);
@@ -438,8 +434,6 @@ public void removePolicies(String sec, String ptype, List<List<String>> rules) {
                 conn.commit();
             } catch (SQLException e) {
                 conn.rollback();
-
-                e.printStackTrace();
                 throw e;
             } finally {
                 conn.setAutoCommit(true);
@@ -514,8 +508,6 @@ public void updatePolicy(String sec, String ptype, List<String> oldRule, List<St
                 conn.commit();
             } catch (SQLException e) {
                 conn.rollback();
-
-                e.printStackTrace();
                 throw e;
             } finally {
                 conn.setAutoCommit(true);