[danbooruservice] Check the blacklist outside the loop

Otherwise we keep on accessing a deleted post and we crash

src/libdanbooru/danbooruservice.cpp

@@ -336,14 +336,22 @@ void DanbooruService::processPostList(KJob* job)
 
         // second check, blacklist
 
+
+        bool inBlacklist = false;
         for (auto tag: post->tags()) {
+
             if (m_blacklist.contains(tag)) {
-                m_currentPosts--;
-                delete post;
-                continue;
+                inBlacklist = true;
+                break;
             }
         }
 
+        if (inBlacklist) {
+            m_currentPosts--;
+            delete post;
+            continue;
+        }
+
         QPixmap pix;
         // QPixmap* pix = new QPixmap();
         bool result;