Remove duplicate operator(==) interface (#1028)

Author: perazz

src/fpm/manifest/preprocess.f90

@@ -58,10 +58,6 @@ module fpm_manifest_preprocess
 
    character(*), parameter, private :: class_name = 'preprocess_config_t'
 
-   interface operator(==)
-       module procedure preprocess_is_same
-   end interface
-
 contains
 
    !> Construct a new preprocess configuration from TOML data structure
@@ -208,7 +204,6 @@ logical function preprocess_is_same(this,that)
 
       integer :: istr
 
-
       preprocess_is_same = .false.
 
       select type (other=>that)