Return false for isInDB if DB does not exist

Fixes #10

crosspost.py

@@ -373,6 +373,8 @@ def jsonRead():
 
 # Function for checking if a line is already in the database-file
 def isInDB(line):
+     if not os.path.exists(databasePath):
+	return False
      with open(databasePath, 'r') as file:
         content = file.read()
         if line in content: