make info message lowercase like the rest

mmdebstrap

@@ -5190,7 +5190,7 @@ sub main() {
                 if (scalar @keyrings == 0) {
                     return " [signed-by=\"$keyring\"]";
                 }
-                info "Finding correct signed-by value...";
+                info "finding correct signed-by value...";
                 my $progress = 0.0;
                 print_progress($progress);
                 for (my $i = 0 ; $i < scalar @keyrings ; $i++) {

tests/logfile

@@ -7,7 +7,7 @@ export LC_ALL=C.UTF-8
 head --lines=-1 /tmp/log > /tmp/trimmed
 cat << LOG | diff -u - /tmp/trimmed
 I: chroot architecture {{ HOSTARCH }} is equal to the host's architecture
-I: Finding correct signed-by value...
+I: finding correct signed-by value...
 I: automatically chosen format: directory
 I: running apt-get update...
 I: downloading packages with apt...