You can't really "join" the .rdata and the .mackt section, since there are other sections between them. It also doesn't have any disadvantage in functionality if you have a .mackt section.

The easiest solution would be to find some free space in the .rdata section, disable "add new section" in ImpREC and recover the imports again, but this time with the address of the free space you found in .rdata.

Or you need to manually move the data from .mackt to the location you want it and adjust all offsets.