Potential fix for #288

BUG: For some reason, the function `extract_function_assembly_features()` might receive a list of basic blocks not containing the function's entry point and Diaphora didn't consider this possibility.

This is a bug I cannot reproduce at all but that, I think, can be easily fixed.

diaphora_ida.py

@@ -2608,11 +2608,12 @@ def extract_function_assembly_features(self, assembly, f, image_base):
     # stuff later on.
     assembly_addrs = []
 
-    # After sorting our the addresses of basic blocks, be sure that the
+    # After sorting out the addresses of basic blocks, be sure that the
     # very first address is always the entry point, no matter at what
     # address it is.
     base = f - image_base
-    keys.remove(base)
+    if base in keys:
+      keys.remove(base)
     keys.insert(0, base)
     for key in keys:
       for line in assembly[key]: