remove LDA_X from q2dx

parser/parser-quantum-espresso/QuantumEspressoXC.py

@@ -646,6 +646,9 @@ EXCHANGE_GRADIENT_CORRECTION = [
         'xc_terms': [{
             'XC_functional_name': "GGA_X_Q2D",
         }],
+        'xc_terms_subtract': [{
+            'XC_functional_name': 'LDA_X',
+         }],
         'xc_section_method': {
             'x_qe_xc_igcx_name':       "q2dx",
             'x_qe_xc_igcx_comment':    "Q2D exchange grad corr",

test/xc_functionals/refactor_test/testuite-xc.ref.log

@@ -536,9 +536,6 @@ qe_xc: 0.00 SLA+PW+Q2DX+Q2DC ( 1  4 19 12 0 0)
   },
   {
     "XC_functional_name": "LDA_C_PW"
-  },
-  {
-    "XC_functional_name": "LDA_X"
   }
 ]
 qe_xc: 0.00 VDW-DF ( 1 4 4 0 1)