fix for shellcheck warnings

dnsapi/dns_lexicon.sh

@@ -31,7 +31,7 @@ dns_lexicon_add() {
   export PROVIDER
 
   Lx_name=$(echo LEXICON_"${PROVIDER}"_USERNAME | tr '[a-z]' '[A-Z]')
-  eval Lx_name_v="\$$Lx_name"
+  Lx_name_v=$(eval "echo "\$$Lx_name"")
   _debug "$Lx_name" "$Lx_name_v"
   if [ "$Lx_name_v" ]; then
     _saveaccountconf "$Lx_name" "$Lx_name_v"
@@ -39,7 +39,7 @@ dns_lexicon_add() {
   fi
 
   Lx_token=$(echo LEXICON_"${PROVIDER}"_TOKEN | tr '[a-z]' '[A-Z]')
-  eval Lx_token_v="\$$Lx_token"
+  Lx_token_v=$(eval "echo "\$$Lx_token"")
   _debug "$Lx_token" "$Lx_token_v"
   if [ "$Lx_token_v" ]; then
     _saveaccountconf "$Lx_token" "$Lx_token_v"
@@ -47,7 +47,7 @@ dns_lexicon_add() {
   fi
 
   Lx_password=$(echo LEXICON_"${PROVIDER}"_PASSWORD | tr '[a-z]' '[A-Z]')
-  eval Lx_password_v="\$$Lx_password"
+  Lx_password_v=$(eval "echo "\$$Lx_password"")
   _debug "$Lx_password" "$Lx_password_v"
   if [ "$Lx_password_v" ]; then
     _saveaccountconf "$Lx_password" "$Lx_password_v"
@@ -55,7 +55,7 @@ dns_lexicon_add() {
   fi
 
   Lx_domaintoken=$(echo LEXICON_"${PROVIDER}"_DOMAINTOKEN | tr '[a-z]' '[A-Z]')
-  eval Lx_domaintoken_v="\$$Lx_domaintoken"
+  Lx_domaintoken_v=$(eval "echo "\$$Lx_domaintoken"")
   _debug "$Lx_domaintoken" "$Lx_domaintoken_v"
   if [ "$Lx_domaintoken_v" ]; then
     export "$Lx_domaintoken"