handle more invalid x264 version strings

setup.py

@@ -118,10 +118,10 @@ def pkg_config_version(req_version, pkgname):
     if r!=0 or not out:
         return False
     out = out.rstrip("\n\r")
-    #workaround for libx264 version numbers:
-    #ie: 0.163.x
-    if out.endswith(".x"):
-        out = out[:-2]
+    #workaround for libx264 invalid version numbers:
+    #ie: "0.163.x" or "0.164.3094M"
+    while out[-1].isalpha() or out[-1]==".":
+        out = out[:-1]
     try:
         from packaging.version import parse
         return parse(out)>=parse(req_version)