build: bump micro version to 1.19.1

Not an official release, just a way to tag the existence of the
QMI_DEVICE_REMOVED signal in QmiDevice.
diff --git a/configure.ac b/configure.ac
index 162d5ae..518d88d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4,7 +4,7 @@
 dnl The QMI version number
 m4_define([qmi_major_version], [1])
 m4_define([qmi_minor_version], [19])
-m4_define([qmi_micro_version], [0])
+m4_define([qmi_micro_version], [1])
 m4_define([qmi_version],
           [qmi_major_version.qmi_minor_version.qmi_micro_version])