Fix a big for Yahoo FA when a ticker has no sustainability info

gamestonk_terminal/fundamental_analysis/yahoo_finance_api.py

@@ -186,6 +186,10 @@ def sustainability(l_args, s_ticker):
 
         df_sustainability = stock.sustainability
 
+        if not df_sustainability:
+            print(f"No sustainability information in Yahoo for {s_ticker}")
+            return
+
         df_sustainability.index = [
             "".join(
                 " " + char if char.isupper() else char.strip() for char in idx

gamestonk_terminal/tests/test_fa_yahoo_finance_api.py

@@ -5,9 +5,19 @@ import unittest
 # pylint: disable=unused-import
 import pytest
 
-from gamestonk_terminal.fundamental_analysis.yahoo_finance_api import info
+from gamestonk_terminal.fundamental_analysis.yahoo_finance_api import (
+    info,
+    sustainability,
+    calendar_earnings,
+)
 
 
 class TestFaYahooFinanceApi(unittest.TestCase):
     def test_info(self):
         info([], "PLTR")
+
+    def test_sustainability(self):
+        sustainability([], "PLTR")
+
+    def test_calendar_earnings(self):
+        calendar_earnings([], "PLTR")