Support Theme: Remove timeframe from pending posts notice

[SergeyBiryukov]

Per the latest ​Support Team meeting:

When a post is held for moderation we currently inform users that it will be reviewed within 72 hours. Unfortunately users get hung up on “72” and don’t read the bit before it explaining that’s the longest period we expect them to wait.

In light of this, we’ll be modifying the string to instead indicate that their post will be manually reviewed by a moderator to hopefully remove the scare element of the high number.

Current text: "This post has been held for moderation by our automated system. It will be reviewed within 72 hours."

Proposed text: "This post has been held for moderation by our automated system and will be manually reviewed by a moderator."

[SergeyBiryukov]

In 7132:

Support Theme: Remove timeframe from pending posts notice.

Fixes #3584.