win32: remove try-catch block of GetModuleFileNameEx (issue2480)

According to the API document, GetModuleFileName is the preferred way to
retrieve the filename of the current process. So we shouldn't try
GetModuleFileName'Ex' first.

Previously system_rcpath_win32() happened to return unicode paths due to
GetModuleFileNameEx (issue2480). This problem is fixed as GetModuleFileName
never return unicode.

mercurial/win32.py

@@ -102,11 +102,6 b' def lookup_reg(key, valname=None, scope='
 
 def system_rcpath_win32():
     '''return default os-specific hgrc search path'''
-    proc = win32api.GetCurrentProcess()
-    try:
-        # This will fail on windows < NT
-        filename = win32process.GetModuleFileNameEx(proc, 0)
-    except:
         filename = win32api.GetModuleFileName(0)
     # Use mercurial.ini found in directory with hg.exe
     progrc = os.path.join(os.path.dirname(filename), 'mercurial.ini')