Update uclibc snapshot config to avoid build stall

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

toolchain/uClibc/uClibc-snapshot.config

@@ -221,6 +221,7 @@ UCLIBC_HAS_FNMATCH=y
 # UCLIBC_HAS_NFTW is not set
 UCLIBC_HAS_GLOB=y
 UCLIBC_HAS_GNU_GLOB=y
+# UCLIBC_HAS_UTMPX is not set
 
 #
 # Library Installation Options