Don't process assignments in conditional expressions (PY-19856)

They lead to syntax error.

python/src/com/jetbrains/python/inspections/PyRedeclarationInspection.java

@@ -172,7 +172,7 @@ public class PyRedeclarationInspection extends PyInspection {
       final PsiElement element = instruction.getElement();
       if (element == null) return false;
 
-      if (element instanceof PyTryExceptStatement) return true;
+      if (element instanceof PyTryExceptStatement || element instanceof PyConditionalExpression) return true;
 
       if (element instanceof PyForStatement) {
         final PyForPart forPart = ((PyForStatement)element).getForPart();

python/testData/inspections/PyRedeclarationInspection/conditionalExpression.py

@@ -0,0 +1,3 @@
+x = 1
+res1 = None if False else x = 2
+res2 = x = 2 if True else None

python/testSrc/com/jetbrains/python/inspections/PyRedeclarationInspectionTest.java

@@ -160,6 +160,10 @@ public class PyRedeclarationInspectionTest extends PyInspectionTestCase {
     doTest();
   }
 
+  public void testConditionalExpression() {
+    doTest();
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {