Changed variables to match the "double-quoted" string standard, as in…

…troduced in \ANXS#319

defaults/main.yml

@@ -590,7 +590,7 @@ postgresql_bytea_output: "hex"  # hex, escape
 postgresql_xmlbinary:    "base64"
 postgresql_xmloption:    "content"
 postgresql_gin_fuzzy_search_limit:  0   # (<= 9.2)
-postgresql_gin_pending_list_limit: '4MB'  # (>= 9.5)
+postgresql_gin_pending_list_limit: "4MB"  # (>= 9.5)
 
 
 # - Locale and Formatting -
@@ -672,9 +672,9 @@ postgresql_transform_null_equals:       off
 
 # These options allow settings to be loaded from files other than the
 # default postgresql.conf.
-postgresql_include_dir: 'conf.d'               # (>= 9.3)
-postgresql_include_if_exists: 'exists.conf'    # (>= 9.3)
-postgresql_include: 'special.conf'             # (>= 9.3)
+postgresql_include_dir:       "conf.d"         # (>= 9.3)
+postgresql_include_if_exists: "exists.conf"    # (>= 9.3)
+postgresql_include:           "special.conf"   # (>= 9.3)
 
 #------------------------------------------------------------------------------
 # ERROR HANDLING
@@ -690,7 +690,7 @@ postgresql_restart_after_crash: on
 # CUSTOMIZED OPTIONS
 #------------------------------------------------------------------------------
 
-postgresql_custom_variable_classes: ''      # (<= 9.1)
+postgresql_custom_variable_classes: ""      # (<= 9.1)
 
 
 #------------------------------------------------------------------------------