package/cryptopp: replace utf-8 space by ascii character

Replace utf-8 NO-BREAK-SPACE (c2 a0) in comment line by simple
ascii space character.

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/cryptopp/cryptopp.mk

@@ -17,7 +17,7 @@ endef
 
 HOST_CRYPTOPP_CXXFLAGS = $(HOST_CFLAGS) -fPIC
 
-# _mm256_broadcastsi128_si256 has been added only in gcc 4.9
+# _mm256_broadcastsi128_si256 has been added only in gcc 4.9
 ifneq ($(BR2_HOST_GCC_AT_LEAST_4_9),y)
 HOST_CRYPTOPP_CXXFLAGS += -DCRYPTOPP_DISABLE_AVX2
 endif