bitbake: server/process: Add missing exception raise

The intent of the code was to catch one kind of error, it was actually swallowing
all exceptions and looping indefinitely. Fix it to work as intended.

This explains some mystery hangs we've been seeing.

(Bitbake rev: d89358c7b8aa69f12b8c384c4fdb493782633494)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/server/process.py

@@ -499,6 +499,7 @@ def connectProcessServer(sockname, featureset):
                 except IOError as e:
                     if e.errno == errno.EWOULDBLOCK:
                         pass
+                    raise
         finally:
             os.chdir(cwd)