【OpenHarmony开源贡献者计划2022】update zh-cn/application-dev/database/database-mdds-guidelines.md.示例代码格式不规范

示例代码格式不规范
Signed-off-by: lizihui1<zhlifm@isoftstone.com>
Signed-off-by: N李子慧 <zhlifm@isoftstone.com>

zh-cn/application-dev/database/database-mdds-guidelines.md

@@ -57,7 +57,7 @@
            kvManager = manager;
        });
    } catch (e) {
-       console.log("An unexpected error occurred. Error:" + e);
+       console.log("An unexpected error occurred. Error: " + e);
    }
    ```
 
@@ -86,7 +86,7 @@
            kvStore = store;
        });
    } catch (e) {
-       console.log("An unexpected error occurred. Error:" + e);
+       console.log("An unexpected error occurred. Error: " + e);
    }
    ```
 
@@ -120,7 +120,7 @@
            console.log("put success");
        });
    }catch (e) {
-       console.log("An unexpected error occurred. Error:" + e);
+       console.log("An unexpected error occurred. Error: " + e);
    }
    ```
 
@@ -144,7 +144,7 @@
            });
        });
    }catch (e) {
-       console.log("An unexpected error occurred. Error:" + e);
+       console.log("An unexpected error occurred. Error: " + e);
    }
    ```
 
@@ -176,7 +176,7 @@
                // 1000表示最大延迟时间为1000ms
                kvStore.sync(deviceIds, distributedData.SyncMode.PUSH_ONLY, 1000);
            }catch (e) {
-                console.log("An unexpected error occurred. Error:" + e);
+                console.log("An unexpected error occurred. Error: " + e);
            }
        }
    });