add /usr/local pkgconfig to search path

Dockerfile

@@ -23,6 +23,7 @@ RUN tar zxf yaz-*.tar.gz && \
     ./configure && \
     CORECOUNT=$(cat /proc/cpuinfo|egrep '^processor'|wc -l) nice make -j$(( $CORECOUNT + 1 )) && \
     make install
+ENV PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
 
 # Install PHP
 RUN mkdir -pv /usr/local/etc/php /var/www/sharedtmp /var/www/privatedata