[catboost] Fix feature_statistics_tutorial

Note: mandatory check (NEED_CHECK) was skipped
ref:d203648025ce9a4f754019ca388bd8ca16719348

Author: nikitxskv

model_analysis/feature_statistics_tutorial.ipynb

@@ -8,8 +8,6 @@
    },
    "outputs": [],
    "source": [
-    "import sys\n",
-    "sys.path.append('/home/nikitxskv/trunk5/arcadia/catboost/python-package/')\n",
     "import catboost\n",
     "import numpy as np\n",
     "import pandas as pd\n",