Explicitly request gettext

Author: sarahec

configure.ac

@@ -1,10 +1,13 @@
 # Update this with each release. Be sure to change VS17/PropertySheet.props too
 AC_INIT([ReadStat],[1.1.9],[https://github.com/WizardMac/ReadStat/issues],[readstat],[https://github.com/WizardMac/ReadStat])
+AC_CONFIG_MACRO_DIRS([m4])
 AM_INIT_AUTOMAKE([foreign subdir-objects])
+AM_GNU_GETTEXT([external])  
+AM_GNU_GETTEXT_VERSION([0.22])
 AM_SILENT_RULES([yes])
 
 # Don't forget to update these too
-READSTAT_MAJOR_VERSION=1
+READSTAT_MAJOR_VERSION=1    
 READSTAT_MINOR_VERSION=1
 READSTAT_MICRO_VERSION=9