-prune option -help output aligned with code

see: .../src/init.cpp#L1063

Github-Pull: #13844
Rebased-From: 312ff01

src/init.cpp

@@ -375,7 +375,7 @@ std::string HelpMessage(HelpMessageMode mode)
 #endif
     strUsage += HelpMessageOpt("-prune=<n>", strprintf(_("Reduce storage requirements by enabling pruning (deleting) of old blocks. This allows the pruneblockchain RPC to be called to delete specific blocks, and enables automatic pruning of old blocks if a target size in MiB is provided. This mode is incompatible with -txindex and -rescan. "
             "Warning: Reverting this setting requires re-downloading the entire blockchain. "
-            "(default: 0 = disable pruning blocks, 1 = allow manual pruning via RPC, >%u = automatically prune block files to stay under the specified target size in MiB)"), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
+            "(default: 0 = disable pruning blocks, 1 = allow manual pruning via RPC, >=%u = automatically prune block files to stay under the specified target size in MiB)"), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
     strUsage += HelpMessageOpt("-reindex-chainstate", _("Rebuild chain state from the currently indexed blocks"));
     strUsage += HelpMessageOpt("-reindex", _("Rebuild chain state and block index from the blk*.dat files on disk"));
 #ifndef WIN32