CI: fix typo in pmOS CI url

.ci/flake8.sh

@@ -1,6 +1,6 @@
 #!/bin/sh -e
 # Description: lint all python scripts
-# https://postmarktos.org/pmb-ci
+# https://postmarketos.org/pmb-ci
 
 if [ "$(id -u)" = 0 ]; then
 	set -x

.ci/pytest.sh

@@ -1,7 +1,7 @@
 #!/bin/sh -e
 # Description: run pmbootstrap python testsuite
 # Options: native slow
-# https://postmarktos.org/pmb-ci
+# https://postmarketos.org/pmb-ci
 
 if [ "$(id -u)" = 0 ]; then
 	set -x

.ci/shellcheck.sh

@@ -1,6 +1,6 @@
 #!/bin/sh -e
 # Description: lint all shell scripts
-# https://postmarktos.org/pmb-ci
+# https://postmarketos.org/pmb-ci
 
 if [ "$(id -u)" = 0 ]; then
 	set -x

.ci/vermin.sh

@@ -1,6 +1,6 @@
 #!/bin/sh -e
 # Description: verify that we don't use too new python features
-# https://postmarktos.org/pmb-ci
+# https://postmarketos.org/pmb-ci
 
 if [ "$(id -u)" = 0 ]; then
 	set -x