E402: Add "if" statement to allowed keywords

Author: EricCousineau-TRI

pycodestyle.py

@@ -1067,7 +1067,8 @@ def is_string_literal(line):
             line = line[1:]
         return line and (line[0] == '"' or line[0] == "'")
 
-    allowed_keywords = ('try', 'except', 'else', 'finally', 'with')
+    allowed_keywords = (
+        'try', 'except', 'else', 'finally', 'with', 'if')
 
     if indent_level:  # Allow imports in conditional statement/function
         return

testsuite/E40.py

@@ -33,6 +33,9 @@
 finally:
     print('made attempt to import foo')
 #: Okay
+if False:
+    import foo
+#: Okay
 with warnings.catch_warnings():
     warnings.filterwarnings("ignore", DeprecationWarning)
     import foo