[DBBackup] Fix JSON formatting

pica-db-backup/config/backup_config.json

 {
-  "mattermost":
-    {
-      "Host": "mattermost-db",
-      "Port": "5432",
-      "User": "MATTERMOST_DB_USER",
-      "Password": "MATTERMOST_DB_PASSWORD",
-      "Database": "mattermost",
-      "Type": "postgres",
-      "Folder": "mattermost",
-      "Cron" : "0 * * * *",
-      "Init-Backup" : "1",
-    },
-  "etherpad":
-    {
-      "Host": "etherpad-db",
-      "Port": "3306",
-      "User": "ETHERPAD_DB_USER",
-      "Password": "ETHERPAD_DB_PASSWORD",
-      "Database": "--all-databases",
-      "Type": "mysql",
-      "Folder": "etherpad",
-      "Cron" : "0 */6 * * *",
-      "Options" : "--single-transaction",
-      "Init-Backup" : "1",
-    },
-    "wekan":
-    {
-      "Host": "wekan-db",
-      "Port": "27017",
-      "Database": "wekan",
-      "Type": "mongo",
-      "Folder": "wekan",
-      "Cron" : "0 */12 * * *",
-      "Init-Backup" : "1",
-    }
+  "mattermost": {
+    "Host": "mattermost-db",
+    "Port": "5432",
+    "User": "MATTERMOST_DB_USER",
+    "Password": "MATTERMOST_DB_PASSWORD",
+    "Database": "mattermost",
+    "Type": "postgres",
+    "Folder": "mattermost",
+    "Cron": "0 * * * *",
+    "Init-Backup": "1"
+  },
+  "etherpad": {
+    "Host": "etherpad-db",
+    "Port": "3306",
+    "User": "ETHERPAD_DB_USER",
+    "Password": "ETHERPAD_DB_PASSWORD",
+    "Database": "--all-databases",
+    "Type": "mysql",
+    "Folder": "etherpad",
+    "Cron": "0 */6 * * *",
+    "Options": "--single-transaction",
+    "Init-Backup": "1"
+  },
+  "wekan": {
+    "Host": "wekan-db",
+    "Port": "27017",
+    "Database": "wekan",
+    "Type": "mongo",
+    "Folder": "wekan",
+    "Cron": "0 */12 * * *",
+    "Init-Backup": "1"
+  }
 }