match flag names in man page

"Full" is an alias for "All", but let's stick to one.

src/mbsync.1

@@ -387,7 +387,7 @@ If \fIcount\fR is 0, the maximum number of messages is \fBunlimited\fR
 (Default: \fI0\fR).
 ..
 .TP
-\fBSync\fR {\fINone\fR|[\fIPull\fR] [\fIPush\fR] [\fINew\fR] [\fIReNew\fR] [\fIDelete\fR] [\fIFlags\fR]|\fIFull\fR}
+\fBSync\fR {\fINone\fR|[\fIPull\fR] [\fIPush\fR] [\fINew\fR] [\fIReNew\fR] [\fIDelete\fR] [\fIFlags\fR]|\fIAll\fR}
 Select the synchronization operation(s) to perform:
 .br
 \fBPull\fR - propagate changes from Master to Slave.