Control locale during Ansible runs

To avoid non-English system locales from breaking tasks that parse
command output expecting English, set the environment variable
LC_ALL=C in each play of securedrop-prod.yml.

install_files/ansible-base/securedrop-prod.yml

@@ -2,6 +2,8 @@
 ---
 - name: Ensure validation is run before prod install
   hosts: localhost
+  environment:
+    LC_ALL: C
   max_fail_percentage: 0
   any_errors_fatal: yes
   connection: local
@@ -10,6 +12,8 @@
 
 - name: Prepare servers for installation
   hosts: securedrop
+  environment:
+    LC_ALL: C
   gather_facts: no
   max_fail_percentage: 0
   any_errors_fatal: yes
@@ -19,6 +23,8 @@
 
 - name: Add FPF apt repository and install base packages.
   hosts: securedrop
+  environment:
+    LC_ALL: C
   max_fail_percentage: 0
   any_errors_fatal: yes
   pre_tasks:
@@ -49,6 +55,8 @@
 
 - name: Configure OSSEC.
   hosts: securedrop
+  environment:
+    LC_ALL: C
   max_fail_percentage: 0
   any_errors_fatal: yes
   roles:
@@ -58,6 +66,8 @@
 
 - name: Configure mailing utilities.
   hosts: securedrop_monitor_server
+  environment:
+    LC_ALL: C
   max_fail_percentage: 0
   any_errors_fatal: yes
   roles:
@@ -67,6 +77,8 @@
 
 - name: Configure SecureDrop Application Server.
   hosts: securedrop_application_server
+  environment:
+    LC_ALL: C
   max_fail_percentage: 0
   any_errors_fatal: yes
   roles:
@@ -81,6 +93,8 @@
   # connection. After that point the admin will to proxy traffic over tor.
 - name: Lock down firewall configuration for Application and Monitor Servers.
   hosts: securedrop
+  environment:
+    LC_ALL: C
   max_fail_percentage: 0
   any_errors_fatal: yes
   roles:
@@ -89,6 +103,8 @@
 
 - name: Reboot Application and Monitor Servers.
   hosts: securedrop
+  environment:
+    LC_ALL: C
   max_fail_percentage: 0
   any_errors_fatal: yes
   vars: