[bugfix] cache 路径写错（对逻辑没影响），DB大小变化判断改为 20kb

LKDBHelper.podspec.json

@@ -1,6 +1,6 @@
 {
   "name": "LKDBHelper",
-  "version": "2.7.1",
+  "version": "2.7.2",
   "summary": "全自动的插入,查询,更新,删除， an automatic database operation thread-safe and not afraid of recursive deadlock",
   "description": "全面支持 NSArray,NSDictionary, ModelClass, NSNumber, NSString, NSDate, NSData, UIColor, UIImage, CGRect, CGPoint, CGSize, NSRange, int,char,float, double, long.. 等属性的自动化操作(插入和查询)",
   "homepage": "https://github.com/li6185377/LKDBHelper-SQLite-ORM",
@@ -10,7 +10,7 @@
   },
   "source": {
     "git": "https://github.com/li6185377/LKDBHelper-SQLite-ORM.git",
-    "tag": "2.7.1"
+    "tag": "2.7.2"
   },
   "platforms": {
     "ios": "12.0",

LKDBHelper/Helper/LKDBHelper.m

@@ -364,7 +364,7 @@ - (void)runAutoVacuumAction {
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
         NSString *cacheDirectory = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES).firstObject;
-        dbAutoVaccumPath = [cacheDirectory stringByAppendingString:@"lkdb-auto-vacuum.plist"];
+        dbAutoVaccumPath = [cacheDirectory stringByAppendingPathComponent:@"lkdb-auto-vacuum.plist"];
         dbAutoVaccumMap = [NSMutableDictionary dictionaryWithContentsOfFile:dbAutoVaccumPath];
         if (!dbAutoVaccumMap) {
             dbAutoVaccumMap = [NSMutableDictionary dictionary];
@@ -395,8 +395,8 @@ - (void)runAutoVacuumAction {
         // 无法获取到DB文件大小
         return;
     }
-    // DB文件大小变化 > 10kb，才执行DB文件优化
-    BOOL const needDBAction = labs(dbSize - lastSize) > 1024 * 10;
+    // DB文件大小变化 > 20kb，才执行DB文件优化
+    BOOL const needDBAction = labs(dbSize - lastSize) > 1024 * 20;
     if (needDBAction) {
         // 执行数据分析，提高后续SQL执行效率
         if (self.enableAutoAnalyze) {