Add missing periods in error messages (#3757)

webapp/components/user_settings/user_settings_general.jsx

@@ -27,7 +27,7 @@ const holders = defineMessages({
     },
     validEmail: {
         id: 'user.settings.general.validEmail',
-        defaultMessage: 'Please enter a valid email address'
+        defaultMessage: 'Please enter a valid email address.'
     },
     emailMatch: {
         id: 'user.settings.general.emailMatch',

webapp/components/user_settings/user_settings_security.jsx

@@ -22,7 +22,7 @@ import {Link} from 'react-router/es6';
 const holders = defineMessages({
     currentPasswordError: {
         id: 'user.settings.security.currentPasswordError',
-        defaultMessage: 'Please enter your current password'
+        defaultMessage: 'Please enter your current password.'
     },
     passwordLengthError: {
         id: 'user.settings.security.passwordLengthError',
@@ -30,7 +30,7 @@ const holders = defineMessages({
     },
     passwordMatchError: {
         id: 'user.settings.security.passwordMatchError',
-        defaultMessage: 'The new passwords you entered do not match'
+        defaultMessage: 'The new passwords you entered do not match.'
     },
     method: {
         id: 'user.settings.security.method',