Merge pull request #2774 from mattermost/mysql-5.7-uuid-fix

Avoided using UUID() as function param for MySQL migration

server/services/store/sqlstore/migrations/000018_populate_categories.up.sql

@@ -26,7 +26,7 @@ CREATE TABLE {{.prefix}}categories (
             REPLACE(uuid_in(md5(random()::text || clock_timestamp()::text)::cstring)::varchar, '-', ''),
         {{ end }}
         {{ if .mysql }}
-            REPLACE(UUID(), '-', ''),
+            UUID(),
         {{ end }}
         COALESCE(nullif(c.DisplayName, ''), 'Direct Message') as category_name,
         cm.UserId,

server/services/store/sqlstore/migrations/000019_populate_category_blocks.up.sql

@@ -16,7 +16,7 @@ CREATE TABLE {{.prefix}}category_blocks (
             REPLACE(uuid_in(md5(random()::text || clock_timestamp()::text)::cstring)::varchar, '-', ''),
         {{ end }}
         {{ if .mysql }}
-            REPLACE(UUID(), '-', ''),
+            UUID(),
         {{ end }}
         {{.prefix}}categories.user_id,
         {{.prefix}}categories.id,