[Bug Fix] struct.unpack("L") varies in size

Although python's documentation says otherwise, the "L" format stands
for long, and could be 4/8 bytes, depending on the compilation. Changed
it to use "I" (int) so the size will be 4 bytes fixed.

Fixes a bug reported in issue CheckPointSW#41.

src/thumbs_up/utils/function.py

@@ -65,7 +65,7 @@ def __init__(self, analyzer, feature_size, inner_offset, classifiers_start_offse
         self._mixed_classifiers = {}
         self._type_classifier   = None
         # seed the random generator
-        numpy.random.seed(seed=struct.unpack("L", ida_nalt.retrieve_input_file_md5()[:4])[0])
+        numpy.random.seed(seed=struct.unpack("I", ida_nalt.retrieve_input_file_md5()[:4])[0])
 
     def isFuncStart(self, ea):
         """Check if the given effective address is the start of a known function.

src/thumbs_up/utils/pattern_observer.py

@@ -82,7 +82,7 @@ def decide(self):
         # Now check for a basic alignment rule
         seen_eas = list(map(lambda x: x[0], self._records))
         # Deterministic results per binary, but still random
-        random.seed(struct.unpack("L", ida_nalt.retrieve_input_file_md5()[:4])[0])
+        random.seed(struct.unpack("I", ida_nalt.retrieve_input_file_md5()[:4])[0])
         while True:
             # Check against two random candidates, and always make sure the representative isn't rare
             measure_candidate = seen_eas[random.randint(0, len(seen_eas) - 1)]